The Detective's Apprentice
by darthtitan
Summary: Eleven-year-old Harriet Potter moves in with Sherlock Holmes after her first-year at Hogwarts. FemHarry!, no slash. Starts after Sherlock is resurrected (S3E1: The Empty Hearse) but before John and Mary's wedding (S3E2: The Sign of Three).
1. Prologue

Prologue

Eleven-year-old Harriet Potter politely nodded as Dumbledore rambled on about the next great adventure and so on. She didn't let on that she was disturbed by his blase dismissal of death, especially after she had come so close to it. 'Not that anyone other than Ron or Hermione would care if I died,' she thought grimly. 'Snape, Malfoy, and the rest of the Slytherins would probably get over their distaste for Muggles long enough to reach out to the Dursleys and hold a celebratory party. A party that would degenerate into violence as soon as Vernon idiotically calls one of the "freaks" as he is wont to do.'

Pleading tiredness and exhaustion, Harriet watched with half-lidded eyes as Dumbledore left the Hospital Wing, blue robes swirling behind him. After confronting Quirrell at the end of the obstacle course and barely managing to keep him away from the Philosopher's Stone, Harriet had been unconscious for the last two weeks. She was gratified by the "tokens of appreciation" at the foot of her bed but was unsure how much of it could be attributed to her status as the "Girl-Who-Lived" and how much to true, abiding concern for _her_ well-being. 'If I weren't Harriet Potter, would these people still bother worrying about me this much?' she wondered.

When Harriet had first entered the Wizarding World, years of cynicism had fallen away, and she had reverted to being the wide-eyed naif that she had once been. Her first glimpse of Diagon Alley only seemed to affirm her sense of wonder at this new world. 'I am finally among others like me. Maybe I can find friends and be normal after all.'

Those hopes were dashed after her first contact with Malfoy in Madam Malkin's. Wizarding-Dudley had shown her that wizards were still people - for all their magic, they were still arrogant, conceited pricks, maybe even more so than the Dursleys or the rest of the Muggles themselves. After Malfoy had dismissed her as a "Mudblood" due to her ignorance about the House system, she had bought several books about recent events in wizarding history, along with some about pureblood-etiquette. They had been most educational as she had read about how the wizarding world had stagnated over the last thousand years - how there had been few advances in the theory or application of magic since the days of the Founders, how power remained in the hands of a select group of families and how these families reinforced their hold by propagating the concept of "pure-bloodedness." Not to mention the highly patriarchical nature of the society.

'Gods, this is worse than the Muggle - garrr, mundane - world,' Harriet had thought. At least in the mundane world, women had gained significant rights over the last few decades and were continuing to make headway. If she could somehow escape from the Dursleys, Harriet could become a teacher, a pilot, an astronaut, a scientist - whatever she wanted to be. The sky was the limit. On the other hand, in the wizarding world, she would most likely be consigned to life as a "housewife;" at most, given her status as the bloody "Girl-Who-Lived," she would be able to become a high-ranking Ministry flunky. 'And don't get me started on becoming a professor at Hogwarts,' she thought grimly. 'As much as I love this school, I do want to experience life on the outside as well.'

Harriet had always possessed an inquisitive, research-oriented mind. Whenever the Dursleys' back had been turned, she had snuck into Dudley's room and used his computer to find the answers to all her questions about the world - how to tell time from the position of the sun, why fertilizer and pesticides helped Petunia's plants grow stronger, how did phones and computers work, and so on. She compounded her inquiries on Wikipedia and Google by perusing books at the school library, which she initially frequented as a means of avoiding Dudley and his cohorts. They would never come within a mile of the place, even to beat her.

When she entered the Wizarding World, Harriet's inquisitive nature did not suddenly disappear; instead, it actually got amplified by the seeming impossibilities around her. She spent evenings talking to the ghosts, trying to understand how they managed to live on after death. Were they just imprints, or were they the actual souls? What did they remember from the moments before they had died?

She began cursing her placement into Gryffindor House within a day itself; the Hat had told her that she would do well in any of the houses, so she had duly pushed for Ravenclaw - the house of the intelligent. The hat even seemed to agree with her decision - she definitely had the necessary intelligence and curiosity, and she prized knowledge for its own sake. But at the last second, something seemed to force it to yell, "GRYFFINDOR!" Looking back, Harriet suspected the blue-robed old man with twinkling eyes who had just left the Hospital Wing a few moments ago.

'I don't know what your game is, Albus Dumbledore. Warning the whole school away from visiting the third-floor corridor - that practically guaranteed that everyone would go check it out at the earliest available opportunity. Worse, since everyone was interested about it, it became difficult to identify the real thief. I mean, how was I supposed to know that Snape was trying to _defend_ the stone when Quirrell and half-a-dozen other professors were also in that corridor at various points in the day but managed to not get bitten?'

'Then, the invisibility cloak - you gifted it to me over Christmas. Why wait that long? If it was a family heirloom as you had claimed, why did you not give it to me as soon as I entered the school? More to the point, you were _waiting_ for me by the Mirror of Erised; you obviously wanted me to find it. So, was this entire "adventure" just a ploy to see how I would fare against Voldemort? To give me experience fighting him because I'm your weapon?'

Harriet rubbed her eyes to ward off sleep. She HAD to think through this now, while her doubts were still fresh in her mind. Living with Dursleys had drilled, 'Question everyone and everything,' into her; by telling her to 'Shut up' every time that she had asked a question, they had ensured that she would go to any lengths to find an answer, whether they knew it or not. And the revelation that they had been hiding knowledge of her magic from her for all these years had only reinforced her belief in that mantra.

"I am the master of my fate, the captain of my soul," she repeated aloud. She loved the poem, "Invictus" - she loved the idea of freedom and independence that it captured. 'I will not let others direct my fate like a puppet on strings.'

'Back to work - Dumbledore carefully maneuvered events so that I would end up fighting Voldemort over the Philosopher's Stone by the end of this school year. From sending Hagrid to recover me and the Stone on the same day to -" she froze.

'What if he positioned Ron and Hermione to be my friends? How do I know that I can trust them?' she thought panickedly. After all, it had been Ron's vehement denunciations of Slytherins that had first poisoned her mind against the house; Malfoy obviously hadn't helped, but he wasn't the entire House, was he? In hindsight, her thrill at meeting a friendly new person and making her first friend had overridden her usual open-mindedness and cautiousness. 'After the hat made its decision, I accepted the decision a little too easily at the time. Heck, I was even glad - thought that I was getting a chance to be with friends.'

'So, in a nutshell, Dumbledore wants me to fight Voldemort. From his refusal to tell me about the reasons that the Dark Tosser went after me and my parents, I can surmise that I am destined to fight him or some hogwash like that. After all, Voldemort could have just taken me and trained me to be his chief servant after killing my parents. From what I've read about his rise, he certainly seems subtle and intelligent enough to do that; it's actually more along his modus operandi than rashly trying to kill a baby.'

'And Dumbledore isn't telling me any of this because - I'm a child? He wants me to stay under his thumb? Why? And how did the Tosser survive all these years anyway? So many questions, so few answers, so little time.'

As Harriet slowly fell into oblivion, a thought reverberated in her head, 'One thing is for sure - I need to get ready. I survived because of luck this time. Next time, I have to end this.'

* * *

Harriet waved goodbye to Ron and Hermione and watched her friends disappear into the crowd in King's Cross Station. She turned and saw her purple-faced whale of an "uncle" waiting for her.

"All right, girl, get in the car," he spit at her.

Double-checking that there were no other wizards around her (they were so easy to tell apart from the mundanes around them; the robes, owls, and trunks were dead giveaways), Harriet shook her head. "'Vernon, I am going to ask you for one favor and one favor only. Take me to this address" - she handed him a slip of paper - "and you will never have to see me again after today."

Vernon's eyes bugged, and Harriet could see the tug-of-war being waged in his puny mind. On one hand, he would have to satisfy Harriet's request, which he wanted to deny just out of habit; on the other hand, he would never have to see the "freak" again.

The latter won out. "All right, girl. Get in the car," he barked.

Harriet obeyed, and the two drove off. Buildings flew by, and the urban milieu eventually gave way to the lush greenery of the English countryside. After what seemed like hours, the car finally pulled to a stop in front of a stately mansion.

"All right, girl, this is your stop. Now, get out! I never want to see your face again!" Vernon said gruffly.

Harriet grabbed her trunk and stepped out of the car daintily. 'Thank God that I got one of the Prefects to cast a Featherlight charm on the trunk,' she thought.

"Goodbye, Vernon. I hope, for your sake, that we never meet again," she replied stiffly. 'Because our next meeting would end in blood, you bastard.'

As Vernon drove off, Harriet felt a pang of sadness - 'what would it be like to actually have a loving family and miss seeing them drive off?' But her practical nature won out, and shaking her head, she walked towards the manor.

* * *

Green eyes met icy blue for a few minutes - neither party broke eye contact.

Then, the owner of the blue eyes finally shook his head in approval - the girl had guts and gumption, he would give her that. He began speaking, "So, Ms. Potter, why did you wish to meet with this old man today?"

Harriet took a deep breath; the first hurdle had been cleared. "Sir, my full name is Harriet Jane Potter, and I am a witch. I read about your family in a book on advances in magical theory over the last five centuries. Until the magical bloodline died out in the 1800s, your ancestors consistently pushed the boundaries of magic in an otherwise stagnant world. Some of those very same ancestors used their considerable knowledge to advocate meager changes in the Ministry's stance towards mundanes and other races. Others provided significant aid to law-enforcement, bringing down many an aspiring Dark Lord."

Raising her hand to forestall denials, she arched an eyebrow and said, "I can read between the lines, you know. Archibald Slytherin, a.k.a Dark Lord Veneficus, fell due to an overpowered, rebounding Stupefy. The last I checked, even the most overpowered Stupefy did not cause someone's head to be blown to pieces."

She continued, "Also, consider Terrence Moriarty from the 1880s. No one even suspected that the Hogwarts Professor was a Dark Lord - until he mysteriously fell to his death from the Reichenbach Falls in Switzerland, and within the next hour or so, authorities found documents proclaiming his status and various misdeeds in a room that he had rented out in a lodge nearby. His considerably large web, which ran through both mundane and wizarding Britain, was brought down in a matter of two years - something that the Aurors definitely could not have done so by themselves."

Looking intently at the old man in front of her, Harriet finally laid her cards on the table. "Mr. Holmes, I know that the only remaining branch of your family has been a line of Squibs. Frankly, I do not care about that; I never did understand the Wizarding World's emphasis on blood purity. If anything, I would actually venture that the aforementioned zealotry is the reason that it has been mired in stagnation while the mundanes have shot ahead. No, merit and talent are what really matter. Mr. Holmes, will you help me understand the criminal mind and provide me with the knowledge and training necessary to bring down Lord Voldemort?"

Mr. Holmes carefully surveyed the young ravenette in front of him. "Ms. Potter," he rasped, "I am not sure whether you are aware of my background, but I was a Special Forces officer during WWII. By virtue of my illustrious family name" - he said this with a ghost of a smile - "I coordinated closely with Indian, British, Continental, and American wizards as we pressed on towards Germany. During that time, I saw the best and worst of your world. I saw magic being used to perform great and terrible things - things that would given any sane man nightmares but also saved millions of lives and hastened the end of the war. I also saw Mr. Dumbledore wage his battle against Grindelwald - a fight for the ages, if I might say so. But even then, I also observed the condescension, the narrow-mindedness of your people, regardless of where they came from - they believed that their magic made them superior."

Raising a weathered hand to reassure a bristling Harriet (who, after her suffering at the hands of the Dursleys, was understandably wary when negative opinions were expressed about magic or magic-users), the elderly Mr. Holmes continued, "I do not mean this as an insult, Ms. Potter. I am actually confirming your own observations. The Wizarding World could be GREAT, but it is held back by its own prejudices. After you defeated Lord Voldemort all those years ago," - again, a ghost of a smile appeared on his lips - "even the most ignorant weatherman noticed the fireworks and the sudden abundance of oddly-robed people in public. That was ten years ago, when CCTVs and the Internet were still coming into their own. Now, in the age of YouTube and Twitter, it is only a matter of time before your ignorant brethren slip up, and magic is revealed to the world. What then?"

"More to the point, for an example of how great wizards could truly be without their self-imposed shackles, I only have to look to my own brother, a man who was formerly known as James Bond." Mr. Holmes chuckled at the look of shock on Harriet's face. "Yes, Bond was my brother and was a wizard - the first one in our line in centuries. After he retired, he authorized a Mundane friend, Ian Fleming, to publish redacted stories about his experiences, both to make enough money to live a life of luxury and to somehow draw the Wizarding World's attention to the mundane's rapid technological progress and rising threat level. As a Holmes, we trained him to think for himself first and foremost, so he thought of himself as a mundane with magic. God knows his ego was large enough as it was - the last thing we needed was for him to believe that he was a God among men like most magicals seem to think."

Mr. Holmes sobered quickly though. "At the height of the Cold War, the Soviets tried something that only the Nazis had attempted before them - they merged their magical and mundane secret services, and the Western world was severely disadvantaged. My brother was the only wizarding MI6 operative, and he was invaluable due to his extensive magical knowledge AND mundane know-how. He stayed abreast of the latest technological developments and constantly experimented with spells on the side. We never published any of that for the fear that the information would somehow disseminate to his Soviet opponents. At any rate, he was so successful that the Soviets couldn't replace the dead operatives fast enough, and mundane-magical cooperatives around the world decided that it was easier to pursue their projects separately, so as to avoid invoking Bond's wrath."

He sighed at this point. "Initially, Bond's stunning success prompted MI6 to search for other magical operatives within the British Wizarding World. Their efforts were preempted by Voldemort's first rise, which started with a rash of Muggle-hunting attacks in the 1950s. As it was, you magicals were extremely suspicious of our world, and with Voldemort's rise, the paranoia only increased. On the Dark Side, purebloods feared that we were sending Muggle-borns to infiltrate and take over their society. On the Light Side, wizards did not want to draw additional attention to the "Voldemort" problem and pull mundane weaponry into the war. They reasoned that at least with spells, they knew what they were getting into. Once guns and nukes entered the picture, there would be no stopping, no control."

"So, our two worlds have remained wholly separate since my brother's halcyon days. We couldn't find willing wizards with my brother's open-mindedness, independence of spirit, and versatility. When he died a few years ago, I thought the dream of integrated law-enforcement was dead. Now, looking at you, Ms. Potter, I see someone with the same potential for greatness as my brother. I see hope for a future where our two worlds can coexist. I commend you for your thorough research and for reaching out to me about defeating Voldemort - but I will entreat you, as an old, idealistic man, to adopt a broader perspective. Because Voldemort is only the latest manifestation of a cancer that has been long eating away your culture. When you state that you want the tools to eliminate him, you actually want tools to cleanse the society as a whole."

He added, "Moreover, those megalomaniacs that Bond fought in the '50s and '60s were just the beginning. Technology is the new magic; I'm sure that you have heard of the so-called 'Iron-Man' who has been engaging terrorists in the Middle East. And even if we leave that aside, we are getting all sorts of new, crazy villains - do look into a Jim Moriarty when you get the time, will you dear? Eventually, these men will find out about the magical world, and the world will burn as good men on both sides will only have half of the picture."

Harriet stared at Mr. Holmes with a gaping mouth. She had not expected to be saddled with the task of integrating the mundane and magical worlds when she had contacted the old man. She had hoped that he could point her to tomes that could help her expand her magical knowledge to hitherto unknown areas, giving her an advantage over Voldemort. At minimum, she had hoped that he would reach out to contacts and get her magical and physical-combat training. But this was so much more.

But before she opened her mouth to laugh at his idea and completely dismiss it ('I can't do this, I'm just a eleven-year-old girl. And what about my own life?'), she stopped and considered. 'He's got a point, you know,' her logical side spoke in her head. 'It's only a matter of time before the mundanes find out about us. Worst-case scenario, mundane terrorists will wreak havoc throughout the world by allying with magical counterparts. I mean, just look at Afghanistan and the Middle East - society is falling apart there. How much longer till magical jihadists join their mundane fellows?'

'And I can't beat Voldemort through pure physical combat or pure magic alone - he outclasses me in terms of the latter and would butcher me before I could get close enough to use the former. I need to beat him on my own terms - terms that he won't even be able to comprehend, much less predict.'

'Above all, I've always been curious and eager for new knowledge. But what's the point of hoarding that knowledge, especially after Voldemort is gone? My parents died for me for a reason. This...this is a reason that I think they would approve of.'

But a part of Harriet rebelled. 'How is this any different from Dumbledore?' it argued. 'At least with Dumbledore, you are only focusing on beating Voldemort. With this guy, you're becoming some sort of Super-Harriet, flying around saving the ENTIRE world.'

Her logical side responded, 'Because unlike Dumbledore, this man is laying all of his cards on the table. And he is offering me invaluable tools and skills to accomplish his (and eventually, my) goals. We're all manipulated at the end of the day as soon as we begin interacting with people. But this path offers me the greatest chance of making my own path and mark on the world.'

Whether Harriet admitted it or not, the prospect of independence and making her own mark cinched the deal. Besides Ravenclaw, the Hat had strongly urged her to consider Slytherin after all. 'Why on Earth it put me into Gryffindor, I still don't understand...unless, of course, I am right about the old goat being a consummate chess-master.'

"Very well, Mr. Holmes. I will keep your ideas in mind," Harriet responded cautiously. "With regards to my original question - can you help me? We can plan for the future and all, but I will need training first..."

Mr. Holmes stared through Harriet for a moment - "So young to be fighting so many." He shook his head to dispel stray thoughts. "Well then, Harriet. I will put you in touch with my sons, Mycroft and Sherlock Holmes. They aren't magic users, but frankly, they will be able to teach you something far more valuable."

"And what is that?" Harriet asked curiously.

Mr. Holmes smiled. "That which separates us from the animals and my wife and sons from the rest of the rabble, including me - deduction and reasoning."


	2. Chapter 1: Moving In

Chapter 1: Moving In

"Well met, Harriet Potter."

"And you, Mr. Holmes," Harriet greeted Mycroft cautiously. The man gave the appearance of being a typical bureaucrat, with his suit and tie, receding hairline, and small potbelly. But his cold, keen hazel eyes almost immediately belied that impression; Harriet felt as though she were being x-rayed by those eyes, the same feeling that she got from Dumbledore's twinkling blue ones.

"My younger brother, Sherlock, is currently looking for a flatmate," he began lightly, "since his previous one, John Watson, recently moved out. Would you be amenable to living with him?"

Clearing her throat, Harriet responded, "Yes, of course. What does he do?"

Mycroft smiled thinly. "You'll find out. Now, if you don't mind my asking, why would a prominent witch such as yourself request aid against Lord Voldemort from a Squib line? Surely, you could turn to other light-sided families, such as the Longbottoms or the Weasleys, even if you don't trust Dumbledore?"

Startled, Harriet blurted, "You know about magic? But your father promised to not -"

Mycroft waved off her concerns. "Yes, I know about magic. No, my father did not expound on your identity or situation to me. The nature of my position is such that I occasionally collaborate with the Ministry of Magic, so I pick up a few tidbits here and there."

"From your scar and your name, I was able to surmise that you were the famed Girl-Who-Lived. Due to the Daily Prophet, I knew about an attempt to steal a valuable object from Gringotts last August and about the recent death of the Hogwarts Defense Professor, Quirinus Quirrell. Since his death, my wizarding sources have apprised me of rumors that the object in question was a Philosopher's Stone."

"But how did you know that Voldemort was involved in this and that I don't trust Dumbledore?" Harriet queried, startled by his rapid-fire deductions.

Mycroft responded, "My mundane sources have reported legends of a wraith and mysterious murders in Albania, both of which suggest a dark wizard of considerable power who is currently weakened. The most prominent recent Dark Lord was Voldemort, and the Daily Prophet obituary noted that Quirrell visited the country last year, so I concluded that Voldemort must have possessed Quirrell in order to get hold of the stone and use the Elixir of Life to strengthen himself. Had he been stronger, we would be seeing mysterious deaths, not to mention heightened Death Eater activity, within Britain itself, and the entire venture might not have even occurred. Moreover, had Quirrell been colluding with anyone else, he would have been alone at the scene of the crime and would have been captured alive, given Dumbledore's well-known distaste for killing."

"Finally, your presence here confirms all of my aforementioned conclusions since your history with Voldemort would have heightened your concerns about his return. Had you trusted Dumbledore, you would have stayed with your relatives this summer, as per his request."

Harriet shook at her head in wonder. "Merlin, that was incredible!" she burst out.

Mycroft smiled thinly at her praise. "Elementary deductions, my dear. Now, we are back to my original question - why did you turn to the Holmes family for aid against Lord Voldemort, as opposed to Dumbledore or the Potters' light-sided allies from the last war?"

Harriet laughed awkwardly. "Well, a part of the reason is because I don't know much about the last war, so I don't know who else to turn to. Most books cover the topic in broad strokes - the locations of attacks, number of casualties, prominent figures who were killed, and so on. But they don't explicate the nature of the resistance against Voldemort, other than simply referring to it as 'The Order of Phoenix.' I have tried asking Dumbledore and my other professors about it, but they dismissed my inquiries, saying that I was too young to know about such dark matters."

"Well, you are only an eleven-year-old," Mycroft said calmly, his eyes inscrutable.

"I may be young, but I had to face Voldemort this past term," Harriet retorted waspishly. "I barely managed to escape with my life from that encounter, and my impression was that Dumbledore set up the entire situation as a 'practice run,' if you will. That, along with Dumbledore's refusal to answer my question about why Voldemort specifically targeted me and my parents in the first place, convinced me that I would eventually have to deal with the madman once and for all before I could move on with my life."

She continued, "Now, why the Holmes family specifically? I first heard of you from my Mum's History of Magic essay, one of several mementos that Professor Snape kept in his desk drawer - detentions are excellent exercises in information gathering. Like I told your father, your family has a history of having dealt with Dark Lords and driving innovation and change within the Wizarding World. I don't trust Dumbledore because he is hiding vital information from me, and I get the feeling that he is primarily concerned with maintaining control over me. Even if I knew who they were, I can't turn to the traditional light-side families since Dumbledore is a hugely influential and venerated figure among the wizarding populace."

"On the other hand, even in the old days, the Holmes were publically neutral; I did not see any mention of the family name in recent wizarding events, so I concluded that you are far enough removed from Dumbledore or Voldemort's influence to be trustworthy allies. It is in your best interest to help me since I have stopped Voldemort twice as it is, and he would be a menace to both of our worlds if he were to return full-force."

Mycroft delicately sipped at his tea. "Excellent reasoning. Are you sure that you aren't interested in politics? With a bit of training, you could be an canny political operator, much like myself."

"To be honest, I wouldn't rule it out," Harriet replied. "However, my highest priority at the moment is to determine a way to beat Lord Voldemort, so that I can live long enough to be whatever I want."

"Very well then, Ms. Potter. Let us proceed to 221B Baker Street then. My brother should be most useful to your endeavors."

"How so?"

"Know thine enemy," Mycroft lectured. "To win a war, one must understand how the enemy operates. At the end of the day, Lord Voldemort is a terrorist, albeit a magically-enhanced one. Let us just say that my brother has expertise dealing with his ilk - I would recommend reading Dr. John Watson's blog and catching up on the Muggle news."

Mycroft paused. "Also, my brother is not aware of your world. Please keep things that way."

* * *

"Hello, little brother. Glad to see that some things never change," Mycroft said tightly as Sherlock looked up from the cadaver on the table.

"Mrs. Hudson, I specifically requested that you tell Mycroft that I was at Barts!" Sherlock shouted.

"Don't bother, Sherlock. I would have known had you left the flat."

"I am in the middle of a very important experiment, Mycroft," Sherlock retorted waspishly. "Either give me the case, or get out."

"Oh, I don't have a case for you, Sherlock. Just a flatmate."

Sherlock dropped his knife and took off his goggles. "I am doing fine, Mycroft. Anderson and his fan-club have already searched the flat - they found nothing and destroyed my sock index yet again. You really don't have a heart, do you?"

"Brother dearest, you have been moping within this flat, doing god-knows-what for a month. You've obviously tried removing John's armchair -"

"Merely to clear the path to my kitchen, so that I could see the experiments on the dining table."

"in order to get over his decision to move into a new place with Mary, but that hasn't worked, has it?"

"Mycroft, I have merely been busy with alternative pursuits lately. Nothing to worry your or Mummy's head over."

"Sherlock, you have been receiving a bucket-load of cases but haven't taken a single one of them. It's only a matter of time -"

"None of them were interesting." Sherlock hesitated and sighed. "And even if you're right - John was a diamond in the rough, and it took two years to train him. What are the odds of finding another like him?"

Mycroft smiled thinly. "Slim to none if we are talking about adults. But what if I give you someone who is more plastic? Someone who would eagerly embrace your particular skill-set?"

Sherlock looked at him incredulously. "You want me to take in a child? Why can't you handle it yourself?"

"Sherlock, I'm still practically raising you. Between you and the British Government, my hands are full as it is; I don't have time to train a child. You, on the other hand, need a companion - an eager, enthusiastic audience, if you will. I am giving you one."

"Please, Mycroft - I don't have time to attend to a whining brat and change its nappies," Sherlock snapped.

"Which is why I am giving you an eleven-year-old. The perfect age really - not too old to be too set in his/her ways but not too young to require constant care and attention."

Mycroft paused and laid the bait - his brother could never resist the lure of competition. "Surely, Sherlock, you're not afraid of mentoring someone? I mean, as I said before, I trained you, and my limited time is the only reason that I'm not handling the current situation myself."

"Don't be ridiculous, brother," Sherlock responded bristling. "And I see what you're doing by the way."

"Of course, you do," Mycroft agreed with a faint smile. "But you're going to give in anyway."

Sherlock gritted his teeth and growled at Mycroft before giving a faint nod.

A young green-eyed ravenette entered the room at the moment. 'Of course,' Sherlock thought grimly. 'Mycroft probably had her stationed right outside the door and told her to wait until I nodded or he gave some inane gesture.'

She held out her hand and said self-consciously, "Harriet Potter."

Sherlock stepped forward and gave a brisk handshake. "Sherlock Holmes."

The girl looked around the room, and Sherlock half-expected a typical exclamation of disapproval or horror. Instead, he was most surprised when a bemused look appeared on her face. "Why are you conducting an experiment with different types of rust?"

"I am studying rust formation on metals from different parts of the city, so as to ascertain the relationship between the amount of rust and the amount of air pollution in the area."

"Why would that matter?"

"Because if there is a directly proportionate relationship as I suspect, then we could develop methods for determining the number of vehicles in an area during a given time frame purely from the rust on a building alone."

"What are you doing with the body then? Or is that a different experiment?"

"Different. I am beating it in different ways to study bruising patterns. For example..."

* * *

Harriet knew that Ron, Hermione, and most of her friends would probably think that her new guardian was insane.

"Blimey, Harriet! The man beats up dead bodies!" imaginary Ron said in her head.

"Harriet, what if he's a serial-killer? Even if he's just a grave-robber, he seems like a law-breaker of some sort," imaginary Hermione cried. "And who on Earth studies rust?"

But Harriet was fascinated by Sherlock's wide-ranging experiments and loved the fact that he patiently answered all her questions. The Dursleys wouldn't even give her the time-of-day, and even Hogwarts professors got irritated if she got a bit too curious. Snape was no better than the Dursleys, McGonagall was ok as long as she stuck to whatever they were doing in class that day, and Flitwick, for all his enthusiasm, was usually hogged by the Ravenclaws. Furthermore, all of them generally exhibited mild irritation if they didn't really know the answer to a question and told her off accordingly.

On the other hand, Sherlock never exhibited such impatience with her. Oh, he definitely got exasperated with her "slowness," for not reaching a conclusion as quickly as him, but even then, he took the time to break down his thought process and show her how he got there. Moreover, even when he didn't know the answer to a question, he considered it seriously and gave it his best shot; at the very least, he pointed her to solid resources.

Starting on her second evening in 221B Baker Street, Sherlock began giving her Latin lessons. "You will find that Latin is an extremely useful language in the demesne of science. It is also excellent as a foundation for learning the other Romance languages, such as French, Spanish, and Italian."

Harriet nodded enthusiastically. She didn't let on that Latin would also be useful in her spell-work as most of the spells relied on a bastardized form of the language.

On the side, Harriet tried to piece together her mentor's occupation.

"You perform a myriad of experiments, many of which deal with human bodies and people's interactions with the environment. You have a skull on the fireplace and are proficient with firearms, as evinced by the perfect smiley-faces that you've shot on the walls. You began with foreign language lessons but have since progressed to algebra, anatomy, and logic lessons. From all this, I surmise that you are a detective of some sort? Or that you do some kind of work related to criminology?" Harriet guessed after a few days.

Sherlock nodded approvingly at her deductions. "I am a consulting detective, to be precise."

Seeing that he wasn't elaborating, Harriet asked, "And what exactly is a 'consulting detective?'"

Sighing dramatically, Sherlock responded, "Officially, I am called in to provide support on cases when the Scotland Yard hits a dead-end. Unofficially, I solve the cases for the Scotland Yard since they're too much of dunderheads to do so themselves."

Biting back a giggle at Sherlock's overt disdain, Harriet queried, "The only thing that seems a bit out of place in all this is the logic -"

"Logic and deduction," Sherlock interrupted, "are essential in every endeavor, none more so than criminology. For example, you only have a limited amount of time to inspect and draw deductions from a crime scene; forensics and bystanders only need a short amount of time to contaminate it. During that time, a solid grasp of logic will enable you to piece together the chain of events that occurred there from a limited data set."

Harriet looked confused.

Sighing, Sherlock said, "You are currently living with me because you are in a position of some importance to Mycroft, and your previous guardians were abusive to say the least."

Harriet paled. "How did you -"

"On the day we first met, I noticed that you did not wear any makeup at all and had only small briefcase worth of clothes. That could have indicated that you came from a poor background, but your speech suggested that you attended a boarding school somewhere in Scotland. Furthermore, when our hands made contact, you flinched a tad bit. This, along with the aforementioned observations, suggested a distant relationship with your previous guardians. There was also the fact that you are much shorter and thinner than your peers, and your eating habits appear to be as appalling as mine. So, not just distant but downright abusive."

'Not good, Sherlock, not good,' John's voice urgently whispered in his head; since John had moved out, that voice had been becoming more prominent in Sherlock's mind, but Sherlock had long practice in ignoring real John, so mental John wasn't too difficult to overcome.

'Hush, John, I'm in the middle of my deductions speech. We have an audience, we have deductions, and now, the presentation will make or break the case.'

"All of this was further corroborated by the fact that you were staying with me now. This doesn't seem to mesh with the fact that you attend a boarding school, so a heiress to a great fortune then? If so, wouldn't your guardians have control of that? Unless they do, and one of the stipulations on that fortune is that you attend the school, so an alma mater for your parents then? Anyway, Mycroft is virtually the British government, so if you got his attention, that meant that you had to be someone important. Now, out with it, who are you?"

Before Harriet could respond, Sherlock barreled on. "I originally thought that Mycroft was simply implanting a spy within Baker Street to keep an eye on me. You were certainly younger than the usual ilk, but your youth could just be a ploy to make me less suspicious. But then, you expressed genuine interest in my experiments (some of the more gruesome ones were purely an attempt to drive you away, by the way) and have shown a unique level of inquisitiveness that even John never displayed, so I became convinced that you were no mere spy. Moreover, even a spy would know better than to pretend to not to know who I am, which suggests that you were isolated until recently. At any rate, back to my question - who are you?"

Harriet panicked. 'Oh no, I can't tell him about magic! Mycroft told me not to, which means that I have no protection from the Statute of Secrecy in this situation. What should I tell Sherlock?'

'Well, well, I'm..." Harriet stammered before a brilliant idea occurred to her.

Raising her head and imitating Sherlock's cool air, she responded, "I took the time to observe your activities and deduce your occupation. Wouldn't it be fair for you to take the time to the same with regards to my identity?"

Sherlock's eyes gleamed at the challenge. "Excellent suggestion, my dear! Rest assured, I will uncover all of your secrets!"

Harriet smiled back at him weakly. 'Whew, bought some time there! Good thing that I got rid of everything but my wand and Invisibility Cloak before moving in. And that I had the foresight to send off Hedwig to Hermione's place.'

Shaking her head, Harriet praised Sherlock effusively. "That was brilliant! Could you teach me to do that?"

"It is just a simple matter of observation, Harriet," Sherlock responded calmly; his gleaming eyes showed that he was extremely pleased by her praise and enthusiasm though. "Most people, I have noticed, tend to see but to not observe. For example, how many steps are there in our flat's stairs?"

"Around twenty?" Harriet guessed.

"Exactly twenty-three," Sherlock informed her. "A seemingly minor detail. But the idea is that a collection of minor details can build up to a valid deduction. Remind me to teach you about probability and statistics at some point, so that we can discuss the weaknesses in my methodology."

"Your brother mentioned that you tangled with a terrorist at some point," Harriet said slowly. "Was that a part of one of your cases?"

Sherlock looked at her slowly and consideringly. 'Hmm, she is young, but even so, she seems woefully uninformed about recent events. Then again, since her guardians were abusive, it is possible that she was far more focused on survival rather than on keeping up to date with current events. But what about the boarding school - wouldn't she have kept up with the news there?'

"I would suggest that you take a look at this blog," he replied smoothly, taking his laptop and pulling up John Watson's blog. "I also suggest that you read the news daily from now on, if only so you can help me find interesting new cases."

* * *

Harriet was reading about the Hounds of Baskerville with great fascination. John Watson was an excellent writer, she decided. The man was able to effectively capture the easy camaraderie between himself and Sherlock, along with Sherlock's own prickly personality, without losing sight of the detective's brilliance.

"John's blog is a bit too romanticized, Harriet," Sherlock said absently as he cut out a liver from a corpse. "I suggested it to you so that you could get an overview of the method and my cases. If you want a deeper understanding, my blog would be better."

Harriet made face. Sherlock may have been a genius, but an effective communicator he was not. His blog WAS interesting, but it was more akin to reading a textbook. An excellent learning experience but low entertainment value.

Mrs. Hudson came up the stairs, footsteps echoing lightly. "Sherlock, dear, someone is demanding to speak with you. Says he has a case that's right down your alley."

"Send him up, Mrs. Hudson," Sherlock said, dropping his surgical tools and rubbing his hands. "I do hope that we have one today."

"Harriet, dear, you're so thin! Are you sure -"

"Mrs. Hudson, red-haired man, waiting downstairs. Surely, it's rude to keep him waiting," Sherlock said sharply.

Mrs. Hudson scowled at Sherlock for interrupting her attempt to mother Harriet. Harriet looked to Sherlock gratefully; while she appreciated the woman's fabulous cooking and obvious solicitousness towards her welfare, she was eager to see the man in action, especially after reading through his cases.

Over the last few days, she had seen Sherlock dismiss several clients after a few moments of deduction alone.

"My pearls are missing -" / "It's obvious that your husband is having an affair and decided to give them to his mistress since you'd never worn them before."

"My aunt -" / "Is a drug addict. She pawned off your car for money. It wasn't stolen by the neighborhood thugs."

Harriet was extremely disappointed as Sherlock solved these cases within mere minutes. 'It would be cool to go on an adventure like he and John did!' she thought mulishly.

And here was her opportunity. A well-dressed red-haired man entered the room.

"Mr. Holmes, the name's Weasley. Lancelot Weasley. I believe that I've been scammed, but I don't know how."

* * *

 **COMING NEXT: The Red-Headed League**


	3. Chapter 2: Red-Headed League

Chapter 2: The Case of the Red-Headed League

"The name's Weasley. Lancelot Weasley, Mr. Holmes. A pleasure to meet you."

Sherlock surveyed the client over steepled fingers. 'Wedding band - married. Clean, well-ironed clothes and well-groomed - still married. Moderate quantity of mud on shoes - walked here from work, so works somewhere in downtown London (possibly 20 minutes away). Is mildly out-of-breath - due to nervousness or just lack of physical exercise in recent times? Business-formal clothing, non-callused hands, and previous details suggest a desk job at a major bank - Barclays, as suggested by the paper sticking out of his briefcase. So, an accountant at Barclays. Which suggests lack of exercise as the cause of his panting. Slight, persistent tic in left hand appears to be a recent development - a gambler then.'

"Mr. Weasley," Holmes interjected, "if you are here for help regarding the fallout from your gambling addiction, especially since you've been using your employer's funds lately, then I'm afraid that you're at the wrong place."

Mental-John winced. 'Again, not good, Sherlock! What if he's here because he's being blackmailed by somebody and has turned to gambling to remedy that situation?'

'John, he's obviously not being blackmailed. Were that the case, he would be showing more signs of nervousness now. In fact, speaking of nervousness, Harriet has seemed a bit pale ever since Weasley mentioned his last name. Acquaintances? Not likely since Weasley would have said something immediately, and she would have showed signs of recognition even before he mentioned his last name. So, a relative of an acquaintance then? That would explain why she recognized his last name. But why would she be so nervous about that?'

'For God's sake, Sherlock!' John exclaimed exasperatedly. 'The poor girl's already uncomfortable about her past - you deduced it was abusive, remember? Maybe you should just let bygones be bygones and let her settle into this new life?'

'John, she practically threw down the gauntlet. It's her own fault for not answering my question about her identity,' Sherlock snarked back. 'I reserve the right to burrow as deep as I want for answers. But in respect for your" - Sherlock gave a mental sneer at this - 'sense of propriety, I will tone down the intensity of the investigation.'

'Just get your head back to the case,' mental-John growled. 'Harriet and Weasley are both staring at you as though you've grown a second head after your previous statement. _Drama queen_.'

'High-functioning sociopath, John. Please refer to me appropriately if you have to insult or otherwise apply other appellations to me.'

"What, how," Weasley sputtered.

Sherlock sighed and laid out his deductions to his two audience members. His mind distantly noted with approval that Harriet was following along raptly.

"I suppose that you were able to deduce that he only started gambling recently because he still isn't used to the tic since he's blinking a bit more rapidly than normal, and his eyes are flitting to the tic every so often. From there, you concluded that he was embezzling because his left hand keeps rubbing his briefcase absently, specifically trying to make sure that it's locked and that no papers are sticking out like the one that was a few minutes ago."

Harriet turned to Sherlock for approval after connecting the dots. Sherlock nodded. 'Positive reinforcement, given her age and previous circumstances, would be efficacious in cementing the lessons.'

Harriet felt a warm glow of pride at the approbation. She also felt relieved that her interjection had successfully distracted Sherlock from the fact that she had recognized Weasley's last name. 'Although he probably noticed it and will follow-up with an interrogation later,' she thought grimly.

The poor accountant stared at the two with a gaping mouth. He shook his head and said with a rueful smile, "Seems like you are as remarkable as your reputation suggests, Mr. Holmes. You got everything to the tee. But I'm not one of your typical gambling clients, Mr. Holmes, in that I'm not being blackmailed - I'm here more for the cause of my gambling. I'm here because I think I've been scammed hard recently."

Sherlock looked at the man impassively. Harriet cracked open a notebook and uncapped her pen; it had been most fortunate that she had stuck to her pen in Hogwarts for the most part, unlike Hermione and the rest of her peers.

"Given how bad the times have been, I have been forced to switch jobs pretty frequently over the last few years. Granted, I haven't been hit as hard as others, but the Recession did hit the mid-level finance types like myself pretty hard, you know?"

"Get to the point," Sherlock ground out impatiently, "or get out. I have an experiment to get back to."

"What he means to say," Harriet covered up hurriedly, "is that the faster you get to the problem, the faster you can get back home to your wife and children. We wouldn't want you to waste your evening with us - isn't that what you mean, Sherlock?"

"I meant exactly what I said," Sherlock responded testily. "You have three minutes to describe the situation. Go!"

"Now, wait a second -"

"Two minutes and fifty-two seconds."

The client's face reddened but thought better of arguing and instead launched back into his story. "I got an email in my LinkedIn Profile a year ago from a group called the Red-Headed League. I was between jobs at the time, and we had just gotten a new house a month before that since I hadn't anticipated being fired so quickly. So, we were in debt and didn't have ready access to cash to remedy that situation, which meant that the league's offer was a godsend. I readily accepted and turned up at the given address the next day for an interview."

"When I got there, there was a huge crowd of red-heads waiting at the door since the lobby wasn't big enough to seat all of them. I nearly turned back there, but the interviewer, a Vincent Spaulding, came out at that moment and called me in."

"Describe Spaulding to me," Sherlock interrupted.

"Err, tall, thin, sickly pale as though he hadn't seen the sunlight in a quite a while."

Sherlock impatiently motioned for Weasley to continue with his retelling of events.

"The applicants around me kicked up a right fuss over that. They yelled and pleaded with him to call them in, but he just shouted right back at them, saying that I had impeccable qualifications and had promptly responded to his calls, unlike the rest of them. I was very chuffed about that - always was proactive after -"

"Being the youngest in a large family, yes," Sherlock interjected. " _Moving on..._ "

'How did he arrive at that conclusion?' Harriet wondered. Something about Lancelot Weasley, aside from his last name, had been rubbing her as being very familiar. 'His mannerisms are similar to Ron's,' she realized. 'Extremely self-conscious - rubbing his hair, wiping off sweat, wiping his glasses frequently; and the fact that he obviously enjoys telling a story to a captive audience.' Ron Weasley had been Harriet's first and best friend, but Harriet had recognized his need to impress and outshine his siblings from their first conversation alone. Lancelot was very similar. 'The only thing is, how has he not recognized who I am yet? Unless...of course! He's the Squib cousin that Ron mentioned to me when we first met!'

"Right, Mr. Holmes," Lancelot said sheepishly, scratching the back of his head yet again. "Anyways, there I was, securing an exclusive interview with this group when a crowd of similarly qualified applicants couldn't. It was a pretty standard interview for finance professionals - where I'd worked, how long, why I'd left my last job, did I know Excel, that sort of thing. The only weird thing was that at the end of the session, Spaulding asked me suddenly how fast I could type. I told him that I was much faster than your average Joe - computers are a big thing and all today, and I'm trying to keep up with the times. He thrust a laptop at me and made me give a demo. My speed must have pleased him because he handed me the job right there with a smile."

"Any other odd behaviors?"

"Err, yeah, now that you mention it. As soon as I entered the office, he stopped to tug my hair and study the locks under the light. Claimed that he wanted to make sure that they weren't dyed red because they wanted to specifically hire a red-headed person."

Sherlock cocked an eyebrow at Lancelot. "What were his hands like?"

"What?"

"His hands, were they callused? Or were they smooth like yours? Did he take any notes at all during the interview?"

"Err, I don't remember what his hands looked like. But he didn't take any notes at all."

"What about his desk? Was it cluttered or organized?"

"Organized for sure. Not a thing was out of place - in fact, when he tipped over a cup of pens, Spaulding broke his questioning to pick it up and put back in the right spot."

"Did he obsess over your appearance or force you to push in the chair on the way out? Was he constantly fidgeting with the items on the table?"

"No, he didn't even touch the table other than that one time. Rest of the time, he was sitting a good distance away from it, hands on his thighs."

Sherlock rubbed his hands. "Go on."

"Err, so where was I? Right, I got job. It paid well - 800 pounds a week - and had decent benefits. The job itself was a bit cut-and-dry though - not really a challenge at all. Spaulding would bring over paper financial statements from the last decade or so for the corporation and ask me to transfer the information over to an Excel spreadsheet. Once I had gotten a decade or so worth of statements in, he wanted me to prepare a report summarizing the company's performance over the time period."

"Were you the only one hired?"

Lancelot shook his head. "No, I was just the first. Afterwards, I saw about 10 others join me at work, and Spaulding mentioned that the regulars who worked from home. I got curious one day and asked him why I was doing this. Apparently, he was working for a client who had always relied on paper records but wanted to cut costs by transferring them online now. The idea was to get the information into spreadsheets and then save them to the cloud. I asked him why the League had so few workers overall and why he wanted red-heads specifically (because everyone I saw, including Spaulding was a red-head). He said that the company was a startup that wanted to digitize small-scale businesses since current solutions were expensive and geared towards the big banks. He also said that he wanted to prioritize red-heads since he had always been picked on as a child for that and had faced this stigma of being poor and being descended from a large family. Honestly, I could empathize with that."

"Did it not strike you that the menial nature of the work was slightly odd, along with the fact that there are undoubtedly laws that prevent discrimination based on red-hair?"

Lancelot flushed. "I was desperate. I've got three mouths to feed and a child on the way."

Sherlock waved his hand dismissively. "Irrelevant. Is that all? If that's the case, then..."

"Wait, I'm not done yet, Mr. Holmes!" Lancelot exclaimed. He hurriedly continued, "A few weeks ago, I got fired from the League since they were apparently done working for the current client and were shipping off to Yorkshire for the next job. I would've been fine with that, except for the fact that I'm now getting emails from various credit card companies thanking me for signing up for a new credit card. The worst part is that the companies apparently tracked the typing patterns on the online application forms, and they're identical to mine! Moreover, there's been no spending on any of those cards, so the police laughed out my claims about identity theft! I've been getting so nervous about being bankrupted and getting arrested all of a sudden that I've taken up gambling, just so that my wife and kids won't be left poor! Please, Mr. Holmes, you've got to help me with this."

"Regarding your colleagues," Sherlock said suddenly. "Did you bother reaching out to them and asking them about their situation in the last few weeks?"

Lancelot laughed wildly. "Not for lack of trying. But they're not responding to any of my emails or phone calls at all. It's not like I know where they live either, so I can't just go up to their doorbell and inquire about their situation."

"Any other details?"

"Well, the other thing about my colleagues is that I can barely remember their faces at all. Suppose that it could just be my horrible memory, but I can't remember anything other than the fact that they all had red hair! I also don't remember any of them ever leaving the offices for lunch or anything - most diligent bunch of office workers that I've seen."

"Excellent, Mr. Weasley. Thank you for your time. We will get back to you as soon as possible," Sherlock said politely. "Mrs. Hudson, be a dear, and show the man out."

* * *

 _Next Morning_

"Sherlock, what are your thoughts on the case?" Harriet asked tentatively, wincing as Sherlock generated a shrieking note from his violin. During the few days that she had stayed here, she had noticed that Sherlock's mood directly varied with the quality of his violin music. Judging by his violin's wailing at the moment, Sherlock was obviously in a pensive mood.

"Use my methods, Harriet, and tell me what _you_ think."

Startled, Harriet recounted her observations about the case. "I would suggest with high confidence that his former employers are the reason that Mr. Weasley has 'signed up' for numerous credit cards recently because this started within days of the League's shift to Yorkshire. Moreover, I checked online for information about the League, but I only found a simple website that gave their old address; it was suspicious that, unlike most other corporate websites, there were little to no details about the staff, other than Vincent Spaulding's contact information. That is particularly unusual for small businesses or startups looking to expand their business. Also, the Red-Headed League hasn't moved to the new Yorkshire address since it contains an age-old sheep farm, which I doubt will sell out anytime soon."

"Very thorough, Harriet," Sherlock said approvingly, "when you could have identified Spaulding and co. as scammers from the preposterous League prerequisites alone. Good work on digging into all aspects of this affair."

Harriet flushed deep red with the praise.

"So, now that we have definitively established the League as a scam, and Spaulding as a perpetrator, can you tell me how they scammed Weasley?"

"Well," Harriet responded slowly, "they could have used a key-logger program to track his keystrokes as he transcribed the paper documents' information into Excel spreadsheets. Then, they could have used Selenium or other automation engines to use those keystroke and/or general usage patterns on credit card websites, thereby tricking the websites into thinking that Mr. Weasley was actually applying for a card."

"Excellent, Harriet! Now, for the most important - why? And please don't just tell me 'identity theft.' There's obviously something grander here."

Harriet laid down her notepad defeatedly. She had been able to answer the "Who" and "What" easily enough using the Internet; she had been fascinated by the concepts of key-logging and web automation. 'Mundane forgery is getting more and more advanced, thanks to technology,' she had thought. 'It almost sounds like magic that they can just record a few usage patterns and get programs to mimic those on a massive scale. Once the necessary programs are ready, all it takes is a tap of the keyboard. Magic, for all its versatility, would require a great deal of input energy to do this. I mean, 50 credit card companies and counting, within a week!'

But Harriet had not been able to identify a larger purpose behind the scam. In fact, as far as she was concerned, this was just a low-level crime, a simple case of identity theft.

"I'm not sure," Harriet admitted.

Sherlock nodded and laid down his violin. "There are a few things that you missed in your notes."

"Oh?"

"One - they targeted Weasley specifically. I checked my newspaper archive and found the advertisement requesting red-headed finance professionals easily enough. But remember that Weasley mentioned that he was specifically picked from the crowd because he had responded to the request via LinkedIn. So, the Red-Headed-League was looking for a red-head, a finance professional, AND someone who was proficient in technology. But you might ask - surely, in today's world, a majority of the world is at least somewhat proficient with computers?"

'Err, actually, I wouldn't,' Harriet thought, 'given that I've seen the wizarding world. The pure-bloods probably don't even know what a computer is.'

"I would then direct your attention to the fact that Spaulding specifically reached out to Weasley on LinkedIn, which suggests that he had been monitoring his status previously. At the very least, it implies that Spaulding was looking for a down-on-the-luck professional since such a person would be more likely to take the job without asking many questions."

"Additionally, the fact that Spaulding was able to pick out that Weasley had once been teased for his red-hair suggests that he is an accomplished con-man - he has experience observing and manipulating his victims. Now, my final question pertains to the bigger purpose behind this entire scheme. I mean, they did pay the man 800 pounds a week, which is no mean sum when the median weekly salary in Britain is 517 pounds."

Harriet suddenly remembered a seemingly minor detail - Mr. Weasley had been unable to remember the faces of his co-workers. 'That sounds like one of those Notice-Me-Not charms,' she thought, 'sort of like the charms that prevent mundanes from noticing the Leaky Cauldron.'

She texted this to Mycroft - Sherlock had already apprised her about the man's bugs in the flat, so she had no doubt that he had been listening in on their conversation. 'I can't believe it - my first case with Sherlock and signs of magic misuse already!'

Mycroft dispelled her excitement with a curt reply. "Occam's Razor - simplest expln is often answer. Is magic really the simplest expln here?"

"Yes!" Harriet texted back.

"No! Think, girl - Weasley was hired bc desperate for job. That + spent most of time poring over old financial records = he barely spoke to others or cared to remember faces," Mycroft texted in response.

Harriet chewed her lip in frustration. What Mycroft didn't seem to understand was that for wizards and witches, magic was often the simplest explanation to various problems. Then again, wasn't that why she was here? So that she wouldn't be like the average magician and would look at the whole picture?

So, Harriet took a step back and tried to look at the big picture. She began writing in her notepad:

 _The main questions are:_

 _1\. What was the larger purpose of this scheme?_

 _2\. Why couldn't Mr. Weasley recognize his co-workers' faces?_

"Sherlock, in your experience, is it normal for people to not remember anything about others' faces?"

Sherlock stopped playing his violin and looked at Harriet thoughtfully. "No. The human brain is a sensitive instrument and has evolved to pick out specific details about other people, if only so we can judge whether they are threats or not. Why do you - Ah, this is due to the fact that Weasley couldn't remember his co-workers' faces?"

Harriet nodded.

"And I suppose Mycroft told you that it means nothing."

Harriet nodded again, scowling. Internally, she wondered at Sherlock's blase attitude at being spied upon by his own brother. 'At least they're not as dysfunctional as the Dursleys.'

"I think it's a major clue - the fact that Mr. Weasley can't identify or contact his ex-colleagues implies that they were in on the scheme," Harriet averred.

"And that could mean some sort of gang activity," Sherlock completed. He rubbed his chin absently, setting his violin down and beginning to pace the room.

"Vincent Spaulding, Spaulding...Aha!" Sherlock cried out. He grabbed his coat and deerstalker, tossing his phone to Harriet along the way. "The game's afoot, Harriet! We need to get to the Barclays main branch soon! Contact Lestrade for me, will you?"

"Wait, what?" Harriet asked bewildered. "Why are we going to Mr. Weasley's workplace?"

"Because that is where the final act of this play will take place."

* * *

Sherlock tapped his foot impatiently. 'What on Earth is taking them so long?' he wondered.

Lestrade came in at that moment. "Sorry, I'm late," he said panting. "Came as fast as I could. What did you need us for, Sherlock?"

Gazing at Harriet, he said, "Egad, Sherlock -"

Donovan cut him off with, "My god, the freak reproduced!"

Harriet gritted at her teeth at the word "freak." "He's not a freak," she protested hotly. "Honestly, you shouldn't insult him just because you can't bother to keep it in your pants with Anderson and focus on your job."

"Listen, kid, I don't appreciate your insinuations -"

"Honestly, it's not that hard to tell what you were doing just before you got this call. Your hair and clothes are all ruffled, as though you just got out of bed. You've also compensated for the stench from your recent...activities...through excessive perfume. And from what I've read in Sherlock's case book, the fact that you aren't wearing your wedding ring today is a big indicator of what you've been up to."

Donovan flushed and gave both Harriet and (a smug) Sherlock a glare with deep-seated loathing. "I'll call the freak, whatever I want," she retorted sneeringly. "Especially since you're as big a freak as he is."

A wave of red fell over Harriet's vision, and she heard the echoes of the Dursleys' shouts - "Freak, prepare our dinner!", "If you do anything _freakish_ , you'll regret ever being born, girl.", "You freak! You got our Duddikins trapped inside that cage with the boa constrictor. Get into the cupboard, freak!" The light bulb above the group exploded in glass, and Donovan suddenly registered that it was becoming harder to breath. As the seconds passed by, she felt as though she were drowning the pool of green that were the girl's glowing eyes.

A strong hand suddenly grasped Harriet's shoulder and gave it a firm squeeze, breaking her out of her trance. Taking a deep breath, Harriet turned her gaze away from Donovan and turned to Sherlock, who looked at her in...concern?

"Thanks," she whispered. Sherlock merely nodded and released his grip.

Harriet began shaking and excused herself from the ensuing conversation between Lestrade and Sherlock, claiming that she needed to use the facilities. She thought, 'I need to get a better handle over myself! I mean, I nearly exposed magic to Sherlock. As it is, he'll probably figure it out within a few weeks, and this only invites more questions on top of my recognition of the 'Weasley' name.'

But as she washed her face in the bathroom, the memories came flooding back - the daily beatings, the longing with which she would stare at a table full of food that she had prepared but could not eat, the dark and dank cupboard under the stairs that had been her home for ten miserable years. When she had first moved into Baker Street, she had loved the fact that she had finally gotten her own room - a place that was all hers, a place that was actually BRIGHT and CLEAN. Yes, the Hogwarts girls dorms had been comfortable, especially since someone had handled the washing and menial tasks for her, but she much preferred her room in Baker Street because it offered an unprecedented level of privacy and security that the shared dorms just couldn't and the cupboard certainly never did.

However, the best part about living in Baker Street was really Sherlock. She reveled living with the genius since he didn't talk down to her but instead tried to bring her to his level. He answered her questions, took the time to teach her when her own primary school teachers had dismissed her as a trouble-maker, and actually looked at her as though she was worth something - as though she had the potential to be great. Even in the wizarding world, no one looked at her in her own merits; it was always through the lens of her parents or her status as the "Girl-Who-Lived." While she loved hearing stories about her parents' days at Hogwarts from the professors, sometimes she wished that they would offer their opinions on her own skills without comparing them to those of her parents. She knew that she wasn't a transfiguration master like her father or a charms mistress like her mother - she appreciated knowing those tidbits about her parents, but she wanted the teachers to help her figure out exactly who she _was_ in her own right.

So, while the term 'freak' had upset her back there, it was more due to the fact that she didn't want its connotations to ever be applied to Sherlock. 'If being normal means being spiteful like Petunia or Donovan,' she thought grimly, 'then I'd rather be a freak. Sherlock is a bloody genius; he might be a bit cold, but at least he thinks that I can be somebody. I'll take that any day, you daft bimbo.'

* * *

"So, you think that -"

"Yes, Lestrade, I think that there will be a robbery here pretty soon. In fact, I expected them to have shown up half-an-hour ago."

"What?!"

"Precisely. I was expecting a distraction, presumably involving gunshots and your standard rigmarole for robberies, while the real action took place among the bank's servers. The idea was that we would use the distraction to sneak back into the server room and foil the perpertrators."

"Why not just ask the bank officials for permission to monitor the server room?"

"Don't be daft, Lestrade - we wouldn't want to alert any insiders that we're onto the entire plot."

At that moment, eight masked men strolled into the bank through its entrance and fired off a round of gunshots.

* * *

Harriet was walking towards Lestrade and Sherlock when the gunmen came in.

Her Quidditch reflexes kicked in, and she instinctively ducked behind a clerk's desk. She noticed the screaming clerk next to her and tried to calm him down.

"Calm down," she said lowly. "Call the police."

The panicking clerk continued to scream and cower. Grabbing the man by his shoulders and forcing him to look into her eyes, she commanded, "Call the police."

The man felt an inexplicable wave of calm pass over him, and he dreamily nodded before complying with Harriet's orders.

Popping her head from behind the desk, Harriet saw Sherlock and Lestrade on their knees, hands behind their heads. Sherlock spotted her and subtly motioned his head in the direction of the vaults. 'Why does he need to go there?'

Harriet shook her head. Sherlock and Lestrade needed a distraction and fast. She could provide that.

She assessed her options. She had a wand but couldn't use it due to the number of ignorant mundanes around her. "Wait, I got that light to explode earlier through my anger - _wandlessly_. Could I do the same again?"

Scrunching her eyes shut, Harriet tried to invoke the same wave of anger again. It was pretty easy - she just had to imagine Dudley's game of Harriet-Hunting, Petunia's scathing comments about her appearance, and Vernon's fondness for beating her with the belt. She added fear for Sherlock's life to this mix, and suddenly, she felt a wave of power wash through her and erupt outwards.

The light fixtures began popping, one by one, and the brightly lit bank began popping into darkness. The gunmen, thinking that there was a sniper or some other gunmen taking out the lights, started waving their guns around frantically, looking for their adversary.

When Harriet popped her head back above the desk again, Sherlock and Lestrade had disappeared.

* * *

As soon as he had gotten out of the bank's main hall and away from the gunmen, Sherlock broke out of his crouch and pressed forward rapidly with his long legs.

"The game's afoot, Lestrade, and we have no time to waste," he said crisply. "You are armed, I suppose?"

Lestrade nodded and followed Sherlock.

The two men rushed into the server room and saw a team of four plugging in a USB into one of the machines.

"Stop!" Lestrade cried out. Sherlock winced. "Idiot," he hissed at him. "We should have taken them out from behind. I don't have a gun, and they outnumber us."

Three of the men raised their guns and aimed them directly at the intrepid pair's heads. "On your knees," the fourth barked.

"Mr. Spaulding, I presume," Sherlock said smoothly.

The team leader laughed. "Well, if it isn't for the famous Mr. Holmes. I presume that Weasley came rushing to you as soon as he saw the credit card emails?"

Pointing to the USB, the leader said, "This USB contains a virus that should replicate Weasley's keystrokes and usage patterns. The virus will spread from this machine to the entire network, eventually transferring over millions of pounds into Weasley's accounts."

Sherlock completed, "And while Weasley is being investigated for embezzling, which he is already guilty of at a much smaller magnitude, you would gradually transfer the fortune over to your own main account. A perfect scheme, Vincent Spaulding, or should I say, Mr. Faulkner?"

"It took you long enough, Holmes," Faulkner sneered. "After Moriarty's death, we were forced to break apart, and you picked us off one by one. Like you, I decided to fake my death in Serbia, so that way, you would turn all your attention to Moran and forget about me. With this fortune and you out of my way, I can restart Moriarty's network. It will be bigger and better than before."

"Any last words, Sherlock Holmes?"

* * *

As the gunmen split up and began questioning each clerk to ascertain who had knocked out the lights, Harriet shushed the clerk next to her with a finger on her lips. Taking a deep breath to still her thudding heart, she crouched and crept slowly past the gunmen towards the hall that Sherlock had motioned his head towards.

"Hey, where do you think you're going?" a voice yelled from behind her.

Breaking into a sprint, Harriet _felt_ a hail of bullets approach her. 'I need to get to Sherlock, I need to get to Sherlock,' she thought desperately, with all her might.

The air around her swirled, and Harriet felt as though she were being squeezed through a tube. She heard a loud 'POP' before she began traveling through the tube. She felt like she was being suffocated and was being sucked into a whirlpool before -

"POP!"

* * *

To say that Faulkner and his gunmen were surprised would be an understatement.

Not only did a little girl suddenly appear out of nowhere, but her appearance caused the nearby machines to go haywire. The servers began smoking and spluttering, and the nearest one, the one which they had inserted the USB into, actually exploded, promptly knocking out two of the gunmen.

Lestrade used the distraction to shoot one of the gunmen in the kneecaps. He hit the howling man in the head with butt of his gun.

Sherlock tackled the distracted Faulkner to the ground and grappled him into a position where he was holding him in a choke-hold. A struggling Faulkner tried to beat Sherlock's face and point his gun towards the detective's head, but Sherlock kicked the gun out of his grasp and maintained his hold. As a finishing move, Sherlock maneuvered his foot behind the man and thrust it forwards. Faulkner was propelled full-force towards the opposite machine and collided against it with a loud "Thud!". He fell to the ground on his back, unconscious. Adhering to the principle of "double-tap," Sherlock grabbed the man by his head and crashed it against the floor once more to ensure that he was well and truly out of the game.

A moment of silence ensued. Sherlock and Lestrade stared at an unconscious Harriet and the four downed gunmen.

'What the s*** just happened?' Lestrade began.

* * *

Fortunately, Donovan had the presence of mind to marshal the officers that she and Lestrade had brought with them and to exploit the gunmen's surprise at Harriet's disappearance. Consequently, by the time that the three made it back to the bank entrance, the situation was well under control, and the Yard was marching the gunmen into a prison van.

As Lestrade exited the bank, he told the smirking Donovan, "Not another word. If you say anything about my blackened, sweaty face, I will stick you in that server room and hold target practice."

Harriet leaned heavily against Sherlock as the two came out of the bank. 'What happened?' she inquired drowsily.

"You" - Sherlock hesitated here - "for the lack of a better word, _teleported_ out of the entrance hallway and into the main group of gunmen in the server room."

Harriet became wide-awake at that. "Teleport...no, that's not possible. I mean, I just followed you -"

"I see," Sherlock said wryly. "In that case, I'm sure that you know that I have tangled with 'Spaulding' before."

"What?" Harriet asked in blatant surprise.

Sherlock rolled his eyes. "I need to teach you to lie and act better, if only so you can fool Mycroft. Frankly, how he believes that he and Father could hide the Others from me, I cannot even imagine. We must discuss your magical education at some point, and you simply MUST take me to Diagon Alley - I haven't found a wizard to solicit such requests from before, you see."

Harriet's head was whirling with these revelations. 'Baby steps...'

"You said you've met Spaulding," she said.

"Yes, I have. In fact, he's a bit lazy, especially since he used that alias prior to faking his death. Honestly, I can't believe it took me so long to recognize it. At any rate, do pick up the pace on John's blog - we can talk more about this once you've read about Jim Moriarty."

Harriet was silent for a few moments as the pair entered a cab. "So, you know about the magical world..."

"Well, I know of it - unlike Mycroft, I can't be bothered to know about what goes on in it. I presume, from your nervousness and reticence, you are a figure of importance there."

Harriet nodded.

"Ok."

"Wait, you're just leaving it at that?"

"Oh no - I will find out why you are famous eventually, along with the rest of your secrets. It's great fun, you see, especially in between cases. But for the moment, I don't care."

"You just want to know -"

"For the sake of knowing, yes. I couldn't care less about the implications."

Harriet shook her head and smiled at Sherlock wryly. "You would be a true Ravenclaw, you know that?"

"What on Earth is a Ravenclaw? Do you have books detailing your terminology and slang by any chance?"

Harriet suddenly sobered and asked Sherlock seriously, "What about Lestrade and the rest of the people? Should I worry about them having seen -"

"None of the bank clerks noticed your teleportation, and the police only stormed the entrance hallway a short while after your disappearance. Mycroft can handle the gunmen, and Lestrade knows from having worked with me for so long to keep his mouth shut."

"By the way, am I correct in assuming that you were guessing that magic may have been involved in this case, which is why you texted Mycroft earlier?"

Harriet nodded and sighed. "I guess I was right about the other coworkers being members of the gang but wrong about the involvement of magic."

Sherlock sagely replied, "Magic may be a primary tool in your arsenal and world-view, but do keep in mind that wizards constitute at most one-percent of the British population, so most crimes don't involve magic. In fact, your smartest magical criminals would pass off a crime as being perfectly mundane even if magical means were involved. (Or at least I would if I had magic and were a criminal.)"

"So, in this case..."

"Yes, Mr. Weasley's inability to remember his own coworkers' faces stems not from magic but from the fact that he was far more worried about his own dire financial straits and that their faces contained many similar features - not surprising since the Faulkner gang is a family affair. Speaking of which, Harriet, we simply must start talking about magic and wizarding culture in code - it would be fun to watch Mycroft storm the place, thinking that you're violating the Statute of Secrecy while we can plausibly deny that."

* * *

 **UP NEXT: The Speckled Band**


	4. Chapter 3: The Speckled Band

Chapter 3: The Speckled Band

As with anything in life, there were advantages and disadvantages to Sherlock's discovery of the fact that Harriet was a witch during the Red-Headed League Case.

On one hand, Harriet no longer had to hide her magic and could actually pick Sherlock's magnificent brain on the subject; she was certain that Sherlock's ruminations alone had taught her more than she would have learned in Hogwarts for the next four years. For instance:

 _"Harriet, have you considered why wizards still use pseudo-Latin for spells instead of English?"_

 _"Because purebloods are power-hungry, traditionalist bastards? I mean, they probably grow up learning Latin and all sorts of spells, unlike Muggleborns, which gives them a distinct edge by the time they get to Hogwarts. Of course, we could also just attribute everything to the fact that wizards are lazy."_

 _Sherlock stared at her thoughtfully. "I assume that purebloods are those born into magical society while Muggleborns are magicals with mundane parents. While your explanation does make sense from a domestic perspective, you might want to also consider the international view. Based on my readings, it appears that all ICW members use the same pseudo-Latin syntax for spells, which certainly expedites communication on an international scale, especially when it comes to erecting border wards. Imagine the nightmare of trying to negotiate between English and French-based wards on top of the usual issues."_

 _He continued, "But I suppose that I need to rephrase my question since we've veered away from my original intent. First of all, I'm sure that you have tried to cast spells in English?"_

 _Harriet nodded._

 _"Did you ever succeed?"_

 _Harriet snorted. "Not even close. My friend Ron tried to use a rhyme to turn his rat yellow when we first met, but the thing just shifted in its sleep. I tried levitating a quill by just saying 'Up!' but it only twitched. I'm still not sure whether that was the wind..."_

 _"But in the bank, you were able to shatter those lightbulbs and teleport without a wand or words."_

 _Harriet stared back at Sherlock thoughtfully. "Good point. Until yesterday, I would have just put it all down to accidental magic, but, aside from the bulb that broke during Donovan's rantings, everything else was pretty intentional. When it came down to it, I was able to do all that when I focused on what I wanted and..."_

 _She struggled to articulate her thoughts. "This sounds stupid, but it was like wishing on a star. Except the trick is that if I wished strong enough, hard enough, I could feel a ball inside me and just had to push it out to do what I wanted."_

 _Sherlock slammed shut the heavy tome that he was reading. "Excellent. That confirms my hypothesis that intent is the key to magic. I assume that you felt drained after the bout of wandless magic?"_

 _Harriet nodded in confirmation._

 _"So, the wand, wand movements, and words are just amplifiers, meant to further hone and sharpen that intent so as to expedite the transformation into reality. I am sure that if you were to sufficiently focus on what you wanted, you could just as easily cast spells in English with your wand."_

 _"Well, that makes sense, except for the fact that with the pseudo-Latin, I barely need to focus at all," Harriet protested._

 _"Which further suggests that the ICW must maintain a set of runes that maps the most basic pseudo-Latin words to the building blocks of your spells. Which in turn makes it easy for all ICW governments to track your spells and impose 'The Trace.'"_

 _Harriet's eyes widened. "So you're really saying that I can practice magic this summer as long as I don't use a wand or use a different language? And the key to all of that is intent?"_

 _Sherlock nodded enthusiastically. "Now enough talk! Do try to lift this book off my calves wandlessly - my feet are falling asleep, Harriet."_

And:

 _"That doesn't even make sense," Harriet growled._

 _Sherlock looked up from his microscope and saw Harriet scowling at the mess brewing her cauldron._

 _"I did everything that the textbook told me to, and I'm supposed to get a blood-red mixture," she muttered irritably. "It's supposed to be a Pepper-Up potion," she added upon seeing Sherlock's inquisitive glance._

 _"The book, please," Sherlock said, holding out his hand._

 _"I did -"_

 _"Just give me the bloody book."_

 _Harriet complied, and Sherlock stared down at the instructions._

 _"Fascinating. Were it not for the usage of magical creatures' parts, this would be yet another chemistry book. Is there a magical equivalent of the periodic table?"_

 _"The periodic what?"_

 _Sherlock sighed and rubbed his temples exasperatedly. "Remind me to add chemistry to our syllabus. For now, come up with a list of core magical elements, the building blocks of all potions. Then, list out how they react with each other."_

 _He added, "The latter is harder than it sounds. Even in regular chemistry, stirring too little could mean that a solute isn't well-mixed, and stirring too much could lead to supersaturation. I assume that magical creature ingredients are far more volatile, so stirring is even more important than usual."_

While Harriet would never be a potions prodigy, she had already learned more from Sherlock in a few days than she had from Snape during an entire year.

On the other hand, Sherlock was essentially an overgrown, self-centered five-year old.

 _"Catch!"_

 _Harriet woke up spluttering._

 _"Bloody hell, Sherlock, you can't just use a water balloon to wake up people up," she said furiously._

 _Waving her off, Sherlock said impatiently, "Yes, yes, you're mad. Now dry yourself using magic. I want to see if the heating process is gradual or instantaneous. "_

 _It was 5 AM in the morning, and Harriet usually woke up an hour later (Petunia and co. mandated that their breakfast should be waiting for them when they came downstairs; failure meant a thrashing at Vernon's hands, followed by an indefinite period of time in the darkness of the cupboard. After all, none of the teachers cared if the 'delinquent' missed a few days.). So, the timing wasn't a huge issue. It was more the fact that she had just been woken up by a water balloon containing icy water. And her clothes were drenched._

 _"BUGGER OFF, SHERLOCK!"_

 _Of course, she had to also dry herself in the process, giving the arsehole exactly what he wanted even as he scurried off. Bastard._

And:

 _"Harriet, I need 10000 Galleons."_

 _"What on Earth for, Sherlock?"_

 _"The Hand of Glory. It would be a perfect addition to the skull on the mantelpiece. Not to mention that it's supposed to be a thief's best friend, whatever that is."_

 _"Sherlock, I'm an impressionable eleven-year-old girl, and you're the 'responsible' adult. That means you shouldn't have even brought me into this obviously dodgy shop in the first place. But now you want to buy an expensive human hand too?"_

 _"Oh, Harriet, don't judge a book by its cover."_

 _"Sherlock, the only reason that we haven't been robbed yet is because we're dressed in rags exactly like some of the hags outside. If we were to take your advice, then we wouldn't have adopted this disguise in the first place."_

 _Sherlock stared at her with his palm outstretched._

 _"No, Sherlock, we're not buying the blood hand."_

 _"Hand of Glory." His palm was still outstretched._

 _The two spent another ten minutes staring at each other, waiting for the other to cave. Fortunately, for Harriet, she had experience with the best of them - no one could beat ickle Duddykins in the spoiled-brat, tantrum-throwing department._

 _All it meant was that Harriet would: (a) never show Sherlock her trust vault and (b) never leave Sherlock in charge of finances during shopping trips. Brilliant detective he may be, but a thrifty spender he was not, especially in this brave new world._

* * *

And then there were days like today - when living with Sherlock was both a blessing and a curse, all in one.

Mycroft Holmes stared at a singed Harriet and Sherlock. Thankfully, the pewter cauldron was no longer on fire, but boomslang skin, goat liver, and various other potion ingredients were splattered onto the flat's walls.

Mycroft's eyes were narrowed into slits, and Harriet was distinctly reminded of Professor McGonagall. She gulped nervously.

Sherlock remained as unabashed and impassive as ever.

"Explain to me," Mycroft hissed at Harriet, "why I shouldn't just ship you back to the Dursleys. I thought that I told you explicitly to not share information about magic to Sherlock. You do realize that you are in violation of the Statute of Secrecy?"

"And you, brother dear," he continued coldly, "must tell me what on earth made you think that helping Harriet brew a volatile potion such as Felix Felicis was a good idea. Especially in this flammable, densely populated urban milieu."

"Mycroft, honestly, you can't tell me that you aren't intrigued by the idea of owning a luck potion -"

"And I suspect that you're going to need plenty of that to talk your way out of this before the firefighters arrive, brother dear. Now, both of you, tell me why I shouldn't just let the firefighters into the flat as it is right now and have the Ministry of Magic deal with you as they see fit."

"Wait, I can explain," Harriet began nervously. "It was my fault; I accidentally used magic during one of Sherlock's cases, and -"

"We can make you a regular supply of Veritaserum, _Myc_ ," Sherlock sneered, cutting off Harriet's nervous rambling.

Mycroft surveyed the pair coolly and nodded in acquiescence. "Fair enough. Just make sure that the neighbors don't see the explosions, and I can send a special squad to help you with the mess. Unlike the regulars, they will be...discreet."

With that, he spun on his heel and headed out the door. He paused at the stairs though.

"And Sherlock - you owe me a case. Before you start grumbling, rest assured that it is a level 7 at least."

* * *

"Mr. Holmes, it truly is a pleasure to meet you today. I would like to apologize in advance for any inconvenience that I may be causing you -"

Sherlock studied the man in front of him. 'Blond, brown-eyed. A botanist/naturalist/outdoors-type, judging by the dirt stains on his fingernails, callused hands, the short-sleeved T-shirt, and muddy sneakers. Not by inclination though judging by the expensive Rolex. Heirloom? Doubtful given the bright sheen, probably a few weeks old at most, and the absence of any engravings. Also, clean-shaven and well-groomed + strong, Old Spice deodarant - definitely vain, concerned about appearances. Or at least the portions that he can control within the confines of his job. Single, never married - no ring, no grooves on ring finger to ever indicate the presence of a ring in the past.'

"You have five minutes, Mr. Stoner."

There was a flicker of irritation in the man's eyes, but it was quickly covered up. "The case involves my older sister, who died a few weeks ago on the eve of her twenty-first birthday. I'm not sure how much you know about -"

"Wizarding culture? The basics. If I'm not mistaken, at seventeen, your sister would have achieved magical majority in the eyes of the Ministry. But in the eyes of Gringotts, she would need to be twenty-one in order to acquire her magical inheritance. From a financial standpoint, I presume that she was set to inherit the Francoise fortune?"

Stoner gaped. "Yes, of course, Mr. Holmes, but how did -"

"Your wand's sticking out of your jeans' pocket. Furthermore, your watch may not be a heirloom, but your earrings clearly state 'Francoise,' and I'm aware that they used to be a major French wizarding family at one point, at least prior to Grindelwald's rampage through Europe. Add in your generally well-groomed appearance despite the naturalist nature of your work, and you are the heir to a magical family."

Stoner cocked an eyebrow. "You truly are as impressive as Dr. Watson made you out to be, Mr. Holmes. At any rate, I will be turning twenty-one in a few days as well, and I believe that I have reason to be concerned for my life given the nature of my sister's death."

Taking a deep breath, he continued, "My sister and I are both studying botany in the University of London. On the magical side, I graduated from Hogwarts with a specialization in Herbology and Potions. Anyway, it was two days before her twenty-first birthday; we were on break at the time and visiting our aunt, Dr. Gwendolyn Roylott. We're not that close, even on the best of days, but she's the only family that we've got, and we wanted to celebrate the momentous occasion together."

"Did you sister have a history of depression or any mental issues?" Sherlock inquired.

Stoner shook his head. "No, she didn't. She was one of the cheeriest people that I've known. In fact, she was a Squib, but unlike so many others, she never begrudged the fact that I got to attend Hogwarts while she didn't. She always pushed me to develop both mundane and wizarding skills, so that I could move between the two worlds easily."

"Go on."

"Around midnight, we heard a high-pitched scream from my sister's bedroom and dashed over to it. The door was locked from the inside, so I had to break it down. Once we got in, we saw..."

At this, Stoner began to choke up.

"She was on the ground, seizing up and writhing in pain. I tried to rush out of the room and get my Potions kit, to see if there was anything I could do to help her, but she grabbed hold of my arm and said, 'The speckled band! Beware the speckled band!' What really stood out to me was the sheer terror in her eyes! She was one of the bravest people that I knew, but whatever it was that killed her scared the wits out of her."

Sherlock stared at Stoner impassively.

"The police completely analyzed the scene, but there were no signs of bullets or breaking-and-entering. Toxicology reports came back clean, and there were no marks on her body. They dismissed the case as a suicide, but I'm not convinced. The terror in her eyes - that was the sign of someone who had seen the Devil himself and was subsequently trying to find someway to get back to Earth alive."

Stoner continued, "Magical authorities didn't find any signs of magic in the area either. There were no foreign potions in her body, no poisons. Her blood was clean."

Sherlock steepled his fingers. "Mr. Stoner, repeat her final words for me."

"'The speckled band! Beware the speckled band!'"

Rubbing his hands together in glee, Sherlock said, "Thank you for bringing this to our attention, Mr. Stoner." Under his breath, he muttered, "For once, Mycroft, you managed to estimate the level correctly."

* * *

"Thoughts, Harriet?"

Harriet looked at her notes pensively. "My first instinct is to blame magic - as usual - but given the absence of a magical signature in the area, I'm going to have to pass on that. I would also suspect poison, but the toxicology report's clean though. We need to take a closer look at the crime scene. We should also interrogate Ms. Roylott; it is her house after all, and the siblings don't seem to have the fondest of relationships with her. In fact, it seems a bit suspicious that they all got together at all for such a significant occasion. Did she invite them? Or did one of them set it all up?"

"Well put. You are getting better at this. Now, off we go, for the game's afoot, Harriet!"

* * *

From the outside, No. 35 Oxford Drive looked like all of the other houses in the area. Harriet felt a shiver of distaste run through her at the uniformity and _blandness_ of the entire suburban neighborhood. From the clean-cut, verdant lawns to the stock, square, white houses, there were little to no differences from Privet Drive. She thought sourly, "There's probably a Vernon-Petunia-Dudley-Harriet group somewhere in this neighborhood too. The dirty secrets that hide behind such normal-looking walls..."

Sherlock rang the doorbell. Their client, Hank Stoner, answered promptly, with a relieved face.

"It's good to see both of you. Thank for following up on my case. Do you want -"

"Take us to your sister's room," Sherlock cut through Stoner's pleasantries.

Again, a flicker of irritation passed through Stoner's eyes, but the man complied.

Harriet's eyes were drawn towards the cupboard at the base of the stairs as Sherlock and Stoner trudged upwards.

"You two go on ahead. I just need to use the facilities."

The duo nodded and continued on.

Harriet quietly made her way to the cupboard door and twisted the knob. The door made a gentle creaking noise as it swung outward.

'Huh - as dark as a I remember. Much cleaner though - no spiders, no toys, no cot. Just the stuff that you would expect to find in a cupboard - cleaning supplies, shoe-boxes, books.'

She had to barely crouch as she entered the space.

'Can't believe that this is where I was living until Hagrid came. I still fit into it pretty well. Who knows? Maybe Petunia will send me back to this hole if I were to ever return to her. Hard to believe that it's the exact same though, besides the supplies, across neighborhoods.'

Even if Harriet hadn't met Sherlock and hadn't gotten her own room at Baker Street, even if she only had the Gryffindor dorms as a baseline, the cupboard still seemed so SMALL and dark compared to before. 'I can't believe that I didn't get claustrophobia after living in such a small space.'

'Maybe this is why I'm so curious. Maybe this is why I keep reaching and striving. I don't want my life to be like this cupboard - dank, dark, restricted. I want to be free to run in the sun, as cliched as that sounds.'

With that, Harriet gently ducked out of the cupboard, closing the door and making her way upstairs.

'No way in hell am I going back to the Dursleys. I need to set something up with Sherlock's homeless network - safehouse, fake IDs, something. I'd rather be a street kid instead, if push comes to shove and I get forced out of Baker Street.'

Suddenly, Harriet froze. She turned her head and looked around wildly, but nothing was there. She heard Sherlock murmuring softly and Stoner responding equally softly upstairs. But there was another voice too, a loud, strong one.

 _Kill. Ssssso hungry. Must feed. Sssstupid humans. Kill._

Heart pounding, she waited a few moments, straining to identify the source of the noise. But it had disappeared just as soon as it had manifested. As much as she would have liked to dismiss it, she walked up slowly, with shaking legs and roving eyes.

* * *

"Harriet, good of you to join us," Sherlock said. "Do you see anything off in this room?"

Shaking away her thoughts, Harriet scrutinized the various aspects of the bedroom closely. Lavendar walls, Hello-Kitty calendar, white drawer...yeah, everything seemed off compared to her life in the cupboard or even Dudley's second bedroom.

But there was nothing to suggest that Stoner's sister had been -

"The bed frame," Harriet realized. "The surface is flat and closed. It's not one of those types that actually rises above the ground."

"Which makes it harder to move, very good. Anything else?"

"There's a vent directly above the bed. Aren't vents usually on the walls rather than on the ceiling?"

Stoner responded, "What does the vent have to do with anything? Sure, Dr. Roylott did some work with the vents a few weeks before we all visited, but that was because the summer was way hotter than usual, and it had been a long time since the AC and heating units had been refurbished."

"Everything and nothing. We still need more data, but the puzzle pieces are falling into place. Thank you for your cooperation, Mr. Stoner."

"My pleasure, Mr. Holmes. Please let me know if anything turns up."

Before they could leave, Harriet hesitatingly asked, "Mr. Stoner, if you don't mind my asking, just who arranged the entire get-together?"

Stoner's jaw clenched as he replied haltingly, "Dr. Roylott, of course. I didn't want to have anything to do with the woman. She may be our aunt, but frankly, my sister and I were happy to move out of this place as soon as we hit our magical majority."

He added hurriedly, "No, she wasn't abusive or anything. She just never understood the magical side of things and preferred to pretend that it didn't exist. It didn't help that my parents, who all of us loved dearly, died during Voldemort's Reign of Terror; she just wanted to keep us safe. But we wanted to know our heritage. Even my sister."

Harriet wasn't a genius like Sherlock. But something seemed off about the whole situation. "Do you mind if we could meet your aunt too?"

"She might not be too happy to see private detectives. She's...trying to pretend that nothing has changed. Her therapist told me that she's still in denial over sis's death."

* * *

"Did you find anything useful in the cupboard?"

Harriet was startled. "How did you -"

"Slightest hint of dirt on your hair." Sherlock brushed it off. "The only place between the kitchen and the stairs with that amount of dirt is the cupboard, given that it's probably not opened that often. You definitely didn't go to the bathroom since I didn't hear any flushing sounds or water running through the pipes."

"Oh."

"Well, did you find anything, or did you just feel the urge to randomly dig through the various nooks and crannies of the house? You're from a suburb, so I'm sure you've seen similar homes before."

Harriet bit back the retort. 'I grew up in that nook and cranny, genius! Why can't you deduce that?'

"Harriet, as much as I hate to admit it, my brother had offered me an excellent piece of advice in the past - 'Caring is not an advantage.' You probably read about it in John's description of the Adler case. Yes, you might be struck by the similarities between Stoner's and your childhood living situations, but in the context of the case, that is irrelevant. All that matters is Stoner's sister was murdered, her aunt _may_ have been involved, and that vent was DEFINITELY involved."

Sherlock may be a genius and an excellent consulting detective. He may have unparalleled skills when it comes to deducing a person's life history from the minutest of details.

But when it came to emotions - god, he was way more broken than she was. 'Yeah, yeah, I don't like pity. I know a 'Sorry' won't fix anything. But does he HAVE to be so casual about it?'

How did he get that way with normal parents? Because she had seen John's brief description of Sherlock's parents. And both Sherlock and Mycroft don't seem like the abused type. If anything, she can picture a couple doting on both of them and pushing them to excel and strive.

'Why couldn't I have gotten that?'

Shaking her head to banish her dark mood, Harriet inquired, "Was there anyone else in the house? Anyone at all?"

Sherlock looked at her puzzled. "I only saw signs of two inhabitants, one of whom was currently out. Why?"

Hesitantly, Harriet described the voice that she had heard.

"You couldn't have mentioned this while we were in the house?" Sherlock retorted testily. "Please repeat it for me."

"Are you sure that you heard it? How loud was it?" he said after a moment of thought.

"Louder than both you and Stoner," Harriet responded flatly. "It came and went quickly, but I know that I didn't imagine it. Could it be a ghost?"

Sherlock snorted. "Hardly. What is most curious is that neither of us heard anything upstairs, which we should have if the voice was as loud as you say it was."

He snapped his fingers. "No matter. What say you about visiting Mr. Stoner's dear aunt?"

* * *

Dr. Roylott the herpetologist stared at the pair harshly.

"What do you two want? Can't you see that I'm busy, you louts?"

"We're here to ask you a few questions about the death of Hank Stoner's sister?"

"Margaret? Beautiful girl, unlike her good-for-nothing brother. Left this world too soon. Why, what's your interest in her?"

Before they could prevaricate, the doctor's eyes widened.

"Hank hired you, didn't he? Just can't accept that he drove her to suicide. Him and his freakish ways. Well, you can sod off."

Upon hearing the f-word, Harriet snapped.

"LOOK AT ME."

Against her will, Dr. Roylott's head turned towards Harriet; she could feel her will being submerged within the pools that were Harriet's green eyes.

"DID YOU KILL HER?"

Dr. Roylott shook her head numbly. Tears began to leak out of the old woman's eyes. "I would...never...kill...her. I...loved..that...child...like..a..daughter. Not...the...boy. Should...have...drowned..the...boy...at...birth."

Harriet continued to stare into Dr. Roylott's eyes and hold her pinned in place for a few long minutes. Searching. Evaluating. Judging.

Just as she could see the utter loathing that Dr. Roylott held for Hank Stoner, she could also see the deep love that she had held for Margaret Stoner.

Of course, Sherlock had taken her pulse throughout the process and duly confirmed the veracity of the information.

* * *

On their way out of Dr. Roylott's herpetological garden, Harriet froze again.

The voices were back.

 _Free usss. Get usss out of thesse cagesss._

 _Stupid two-legssss. Poking and prodding at usss in these cagesss._

 _Back. Back. I want proper meat, foolssss._

"Harriet, what's wrong?" Sherlock asked her, frowning.

Harriet ignored him; as she looked around, she only saw the snakes. She didn't see anyone.

"That noise," she said slowly, "do you hear it?"

"I'm only hearing..." Sherlock said, trailing off as his eyes became distant.

He returned to Earth with a faint smile. "I got it. We need to go back and ask Dr. Roylott one other question though."

"What question? And what did you just figure out? What am I hearing? Sherlock, for god's sake, just wait a moment, and explain, will you?"

* * *

"It was the perfect crime, wasn't it, Hank?"

Stoner jumped, startled by Sherlock's voice.

"Mr. Holmes, what are you doing here? I apologize if I seem impolite, but it's been a long day, and -"

Sherlock raised a gun and pointed it at Stoner.

"Please, sit down, Hank."

Stoner sat down with shaking hands.

"Whoa, man, take it easy. I'm not sure what you think is going on, but -"

"Please drop the act, Hank."

The man stopped shaking, and a cold, flinty look appeared in his eyes.

"Much better. Please tell me if any of the following deductions were wrong. You have resented both your sister and your aunt for a very long time - your aunt for rejecting magic and your sister for claiming your aunt's affections. You could have lived with that though. No, what really cut you was the fact that your parents' will listed your sister as the primary inheritor, even though she was a Squib, and they knew that due to the very nature of the inheritance test. While most magical families disinherit Squibs on birth, your parents didn't. To make matters worse, both your aunt and your sister were pushing you to work in the mundane world since they were terrified by the magical world's anti-Squib prejudice and saw far more opportunities here instead. But you, you were enamored with the magical world. It was a way for you to finally step out of your sister's shadow. You may have hated being the freak initially, but you eventually embraced it, especially given your placement in Slytherin. Oh yes, we checked the Hogwarts register; it's surprising how fast owl mail can be even if the Ministry of Magic itself is completely outdated and inefficient. You adopted the pureblood supremacists' ideology readily, and by eliminating your sister, you finally had the chance to make a bold entrance back into pureblood society. To finally bring back the Francoise name. The only remaining obstacle was your -"

"My aunt. Well done, Mr. Holmes. I knew that it was a risk to come to you. I was really hoping that you wouldn't talk to my aunt or that she would drive you away, as she is wont to do. Not sure how you managed to get a word from her that didn't involve 'freak' or 'delinquent.' Anyway, the idea was to get you to suspect her, shift all the blame off me."

Sherlock nodded. "As for the murder itself, I presume that you stole a snake from your Aunt's garden. The Naja naja or India cobra, to be exact."

Stoner chuckled. "Very good, Mr. Holmes. You really were thorough, weren't you? Yes, I stole a Naja naja; it wasn't like she would notice one missing snake out of so many others in that place. I replaced its venom with -"

"Beozar. Ironic that an element known to cure many poisons can become a poison in itself in large quantities. Also untraceable since it dissolves into blood seamlessly if there is no poison to bind with."

"How on Earth - you know what, never mind. I guess I overplayed my hand; I should have gone to the Scotland Yard instead. My uncle used to always talk about his protege, Mycroft Holmes, and how brilliant he was. Then, I saw your blog. Thought that I could use the two of you to wrap things up before the renewal of the Francoise line. Still can, as a matter of fact."

Sherlock looked puzzled at Stoner's final statement.

Stoner snorted. "Oh for Pete's sake, you Muggle genii are so stupid. So confident in your own abilities, believing that just by hanging out with Magicals or reading our books, you can understand us or magic. You filth know NOTHING. You're like blind painters, trying to grasp something that's forever out of your reach. Look up, Mr. Holmes. Look up, and meet your doom!"

The vent above Sherlock opened abruptly, and something fell onto the floor, hissing and spitting.

Sherlock scrambled out of the sofa and jumped away with flashing eyes. He frantically searched the floor and pointed his gun at the ground, but in the darkness, he could not see clearly.

Stoner used the opportunity to jump on the man and knock the gun away. Sherlock grabbed him in a chokehold and tried to throttle him into unconsciousness.

But Stoner forced Sherlock to let go by meting out several punches to his solar plexus. As Sherlock retreated wheezing, Stoner scrambled towards the gun.

Sherlock stood up and looked around wildly - for the snake on the ground, the gun, Stoner, anything...

"Arrrrggh," Stoner screamed.

Sherlock backed out of the hall, fingers scrambling for the lights. He found the switch and turned it on.

One angry Indian Cobra - the speckled band - was slithering out of the room, away from a wounded Stoner. Blood was dripping freely from two deep punctures on Stoner's left hand, the one that had been closest to the gun, and Stoner was already entering shock, shivering and writhing in pain.

By the time his death throes had settled, and a glassy look had entered his eyes to mark his entry into the land of death, the punctures had already sealed themselves up - thanks to the curative properties of the beozar that he had replaced the Indian Cobra's venom with, a painful substitution process that had only served to enhance the poor snake's anger.

Sighing, Sherlock stepped past Stoner's still body and picked up the gun. He weighed it for a few moments in his hand and opened the chamber.

It was empty.

"Thought so. Well, it's good that he didn't attack earlier," Sherlock murmured. Raising his voice, he said, "You can come out now, Harriet."

Harriet exited the cupboard under the stairs.

"I thought that I told you to remain with Dr. Roylott, explain the situation to Lestrade once he got there, and then direct him over here?"

Harriet snorted.

"Oh yes, you had the situation well under control. You went in with John's gun without even checking whether it was loaded, and you decided to wait in the one spot in the hall from which he could still literally get the drop on you. No, you were doing fine."

"I had to confirm whether he used beozar as the substitute for traditional venom. That was the only point that I was still unsure about since we only noticed that after several experiments on rats. The differences between human and rat physiology were significant enough to warrant further investigation, which has now been settled."

"In other words, you were bloody curious and couldn't resist a chance to show off. I hope that your brush with death was worth it."

"Nonsense, Harriet. I was never in any danger. Not with a snake-charmer such as yourself around."

Sherlock's eyes softened for a moment, and the man hesitated. "Thank you."

Harriet simply nodded in acknowledgement.

As Sherlock pulled his coat back on and went outside to greet Lestrade (who characteristically arrived at the end of the party), she pulled a cage out of the cupboard and went off to the kitchen to wrangle a snake.

Honestly, she wouldn't blame it for putting up a fight. Heh, she might even let it go after taking a picture for evidence.

* * *

 **Up Next: The Sign of Three**

 **"The Sign of Three" (Sherlock S3E2) is actually what inspired me to write this fic in the first place. How would a female Harry affect the proceedings of John's wedding?**

 **To all favoriters/followers, thank you for expressing interest in this fic. I am humbled by the enthusiasm and would greatly appreciate your feedback for this latest chapter.**


	5. Chapter 4: John's Wedding - Part 1

This was it. The moment that he had been waiting over a year for.

"Yes, yes, take the bait, you bloody bastards," Scotland Yard's Inspector Gregory Lestrade muttered as he watched the Waters gang load piles of cash into black duffel bags over the security feed.

"I can't believe it. We've finally cornered them," Donovan said, shaking her head in disbelief. "Good show, boss."

Lestrade ignored the praise and effusive backslapping that the rest of his colleagues followed up with; his eyes watched the screens hungrily as the gang leader, carrying several bags stuffed to the brim with cash, walked towards the door of the safe room.

"Got you now," he said with a smirk. Turning around, he eyed the weedy technician and gave a single nod, upon which the technician entered a slew of commands on his laptop and pressed "Enter."

Inside the thick, gunmetal safe room door, green lights blinked to life on a series of Raspberry PIs, all of which were directly connected to actuators that controlled the motion of the door. In this case, the door promptly began retracting with astonishing alacrity.

Lestrade flat-out guffawed as the gang leader rushed towards the closing door, and the rest of the startled gang followed mindlessly, abandoning the bags that they had been so diligently filling up. "Not this time, you don't."

Bzzzzz...

Spinning around, he stalked out of the room, his fog coat billowing about him like Severus Snape's robes (not that the latter would have appreciated the comparison). Donovan followed closely behind him, the smirk on her face a mirror of that on her boss's.

"You know, the look on their faces right now was totally worth the last year of seeing those smug arseholes skip off in court."

Bzzzzz...

Lestrade snorted as he turned a corner. "Oh, you're telling me. I still don't know whether it was worth antagonizing the new Chief Superintendent though. And I was really holding out for a promotion since the girlfriend isn't super-impressed with my current posting."

"Oh, lighten up, boss. Pretty sure that this is the upward push you need."

Bzzzzz...

"Sorry about that; my phone's been a bit twitchy lately. Hang on, let me shut it up," Lestrade declaimed, brows furrowing in annoyance as he dug his cell out of his pockets.

His joviality vanished swiftly.

"Go on ahead without me."

"What, what's going on?"

"Baker Street."

"The freak? But this is it - you were just telling me that this is the break that you've been waiting for. You can't go now."

Lestrade merely shook his head, mumbling apologies as he turned around and raced towards the parking lot.

"All right, men, I need a squad to follow my car to Baker Street. If you can, Davies, alert Mycroft and direct Special Forces there ASAP. The rest of you lot, secure the prisoners in the vault. I expect that we'll only need about 10 officers for that," he rattled off into his mic as he threw open the door of his BMW 5 Series.

'Oh god, I hope I'm not too late. Don't worry, Sherlock, I'm on my way...'

A record-breaking ten minutes later (never had Lestrade been gladder about his high-ranking position in the Scotland Yard, which exempted him from ordinary folk's concerns about parking tickets), a silver BMW 5 Series skidded to a halt in front of 221B Baker Street; Lestrade stumbled out of the car, threw open the front door of 221B (startling poor Ms. Hudson into dropping something white in the process), and dashed up the stairs.

"Shhh-Sherlock, I'm here. What's going on? Is everything all right?" Lestrade asked, gasping and swiveling his head wildly. Reflexively wrinkling his nose, he couldn't help but ask, "And what in God's name is that smell?"

"Ah, Gatiss, I am most pleased by your alacrity; given that it is rush-hour and that you are normally a relatively conservative driver, I fully expected you to be here ten minutes later. No matter - I need your help in this task, the biggest challenge that I have ever undertaken in my life."

Through long practice, Inspector Gregory Lestrade ignored Sherlock's inability (or refusal) to recall his first name. "Well, what is it?" Whatever it was, it had to be big. The last time that Sherlock had summoned him for help with the "biggest challenge of his life," he had ended up faking his death and disappearing for two years in order to dismantle Moriarty's criminal networks.

Sherlock stared straight into Lestrade's eyes with his piercing blue orbs, fingers steepled and body pivoting away from the laptop towards Lestrade.

"Will you help me write a best man's speech?"

Lestrade stared at him in bemusement, chest still heaving from his recent exertions. "What?!"

"Best man's speech? For John's upcoming nuptials? Come now, Gavin, surely that hasn't slipped your perfectly average mind?"

Gaping slightly, Lestrade merely shook his head. "Sorry, I thought...I thought that you were in trouble."

Sherlock's keen gaze grew sharper, and Lestrade suddenly felt as though he were a schoolboy being reprimanded for his hastiness by his father. "Ah, I see. I assume that we will shortly be joined -"

BOOM!

The pair ducked and jumped near the windows as an explosion went off in Sherlock's bedroom, and the bedroom door was ripped clear off its hinges and flung into the back of John's chair.

"Harriet! I thought that I told you to wait for another half-hour before adding the crushed liverwort! Felix Felicis is an extraordinarily time-sensitive potion!"

Smoke poured through the kitchen and into the living room. Lestrade squinted and made out a thin, coughing figure coming out of the bedroom.

"No, you specifically told me to add it right now! At 4:30!"

Sherlock blinked and looked at the IPhone on his table. "Oh. It's 4:30."

Before any more banter could be bandied about, a flood of water crashed through windows, utterly drenching Lestrade, Sherlock, and Harriet. Concurrently, the loud noise of a helicopter's spinning blades filled the room, even as the accompanying gusts of air threw the loose papers and various small knicknacks in the flat into disarray.

"SHERLOCK! You've got a client!" Mrs. Hudson's voice echoed up the stairs, somehow managing to remain audible despite the ongoing chaos.

It was yet another ordinary day in the extraordinary life of Sherlock Holmes and Harriet Potter.

* * *

 **CHAPTER 4: JOHN'S WEDDING - PART 1**

* * *

"BEBEBEEP BEBEBEEP!"

The clock's red LEDs shifted and flashed "6:30." Despite the early hour and London's typically dreary weather, the first rays of sunlight danced through the window, promising a glorious day of light and laughter.

It perfectly fit John Watson's mood. Even though he hadn't been able to get a wink of sleep the previous night, and his chest was clenched with nerves, a larger part of him was filled with excitement and anticipation.

Today was the day - the day when he finally married the woman of his dreams, Mary Morstan.

He and Mary had met shortly after Sherlock's "death." Since he hadn't known at the time that Sherlock had faked his suicide in order to secretly eliminate the remainder of Moriarty's network, John had been understandably devastated. For weeks on end, he hadn't been able to eat or sleep properly as images of Sherlock's bleeding, cooling corpse on the sidewalk kept flashing past his eyes; Mrs. Hudson had been so worried about him that she had practically maintained a one-woman suicide watch over him, going so far as accompanying him to work.

Fortunately, around a month later, he had hired Mary as his new receptionist, and being the astute woman that she was, she had instantly recognized his intense trauma and PTSD. Things progressed from there as Mary fast became his friend, confidante, and eventually fiance. She helped him straighten out his life and regain focus and clarity. Of course, life wasn't quite as...exciting...without Sherlock (not that he would ever admit it to the detective, given his already bloated ego), but it was good enough.

Then, Sherlock returned. In the middle of a date with Mary. Right when he was about to propose to her.

The bloody, arrogant arse.

Several days of silent feuding, a kidnapping, and a defused bomb later, the duo had made up and resumed their friendship. Granted, given John's own increasingly lucrative practice and his courtship with Mary, they hadn't been able to spend as much time together as before. Still, it was only a few weeks, right? John hadn't expected the detective to change anything drastically in his own life.

Oh, how wrong he was. Two weeks after they had made, John returned to 221B Baker Street after a long day at his office; he was eager to unwind with Sherlock and sync up on the latest cases, if only to erase the mind-numbing nature of dealing with a stream of patients with an assortment of problems.

Climbing up the familiar steps, John froze at the open doorstep upon seeing a black-haired waif mixing together various murky-looking chemicals.

Taken aback, he looked down bemusedly at the girl, "Errr..."

"SHERLOCK!" she hollered without even looking up from her work. "YOU'VE GOT A CLIENT!"

"Wait a second, I'm not -"

Sherlock came running out of the bedroom, wild-eyed and with a gun in his hand. "Really?! Oh finally, I was wondering what it would take for criminals and murderers to come back out - it's almost as if they were on an extended vacation!"

John cocked his eyebrow. 'Only Sherlock.'

"Oh, it's just you - good to see you again, John," Sherlock said airily.

"You too, Sherlock," John responded, moving towards the raggedy armchair betwixt the living room and kitchen. His armchair. "Still haven't gotten rid of it, I see?"

"Definitely not. I find it useful to speak to it from time to time when the stupidity around me gets to be too much."

The girl snorted at that.

"Yes, I'm talking about you! How could you mix bitterwort with mandaroga root?" he directed at her heatedly.

"You told me to try categorizing them like chemicals in the periodic table! The only way to do that is to actually experiment; if we're lucky, we get useful results, and if we're not, then we get magic smoke. Thank God for Mycroft."

"Never utter that blasphemy again," he said flatly, shuddering.

John coughed and interjected before the argument could resume, "Um, Sherlock, who is this?"

"Oh yes, introductions. John, this is Harriet. Harriet, this is John Watson."

Harriet's head shot up when Sherlock finished saying his full name, her green eyes turning round behind her glasses. Suddenly letting out a squeal of delight, she dropped the chemicals and dashed off to what was once John's room. In the span of a blink, she was back before John with a notebook and a pen.

"Oh my god, it's such a pleasure to meet you! I love your blog and the way that you wrote about all of your adventures with Sherlock. It's so amazing, especially given everything that he gets up to, like the Baskerville case and -"

"Yes, yes, Harriet," Sherlock cut her off irritably (and since John knew him so well, he could also see the traces of amusement). "If only you could spare the same level of enthusiasm for _my_ blog."

Harriet rolled her eyes. "Sherlock, nobody wants to read about the 40 different kinds of mold that could grow on bricks and concrete for more than a paragraph at most. You go on about it for 20 pages! It's more interesting to consider that information in a practical context."

"Underappreciated as always," Sherlock sniffed.

Harriet, however, had turned back to John. "Could I please have your autograph?" Suddenly turning shy, she coughed and shifted her feet. "I mean, if you would like to, that is. Sorry about that, it's just your blog is so well-written, and Sherlock always goes on about how invaluable your presence was in all those cases."

John couldn't help smirking at Sherlock, who was pointedly glaring at the apartment ceiling now. "Of course, Harriet. It's a pleasure to meet you, and I would be delighted to give you my autograph," he said magnanimously, accepting the proffered notebook and signing right below Sherlock's scrawl on the first page.

"Before your head explodes with excitement," Sherlock drawled, "you might want to check in on your concoction again. The flies' wings you added in just as John walked in should be kicking in now, and you only have a minute more to execute the next step."

Squeaking, Harriet rushed off to her project - Did Sherlock just say flies' wings? And was that a cauldron? - all the while clutching her precious notebook close to her chest.

"So," John started with a raised eyebrow, "I never saw you as the child-rearing type."

He glanced again at the cauldron and the humming girl who was stirring it like an old-fashioned butter-maid, or dare-he-say-it, a witch. Then again, this was far from the oddest scene that he had ever encountered in these hallowed rooms. Naked Sherlock, stoned Sherlock, impatient but coping Sherlock shooting walls, eager Sherlock rushing out of the flat to solve a case even as he forgot the severed head and assorted bones on his table - no, this was positively domestic for Baker Street.

Come to think of it...

"Gathering from the gun in your hand, I deduce that you haven't had any cases recently," John remarked dryly. Turning more serious, he continued, "Please don't tell me that you decided to adopt Harriet because you were bored."

"Harriet's parents decided to go on an extended vacation, and they needed someone to look after her. Mycroft insisted that I get involved and threatened to set Mummy upon me otherwise."

"She's not the prime-minister's long-lost daughter, is she?" John half-joked. Given that Mycroft was virtually the British government, one could never be certain whether his assignments and requests were as innocuous as they appeared superficially.

"No, she's my third-cousin, twice-removed," Sherlock said, waving his hands dismissively. "Or second-cousin, thrice-removed? Meh, at that distance, it all blurs."

Well, there was certainly a faint resemblance between the duo - copious black hair (unruly curls in Sherlock's case though in contrast to Harriet's own straight lines pulled back into a ponytail), a gleam of keen intelligence in the eyes, and a lean physique. While Harriet was somewhat short for her age - 12 or 13 at most - John was highly certain that she would eventually tower over her peers given her own long legs and Sherlock and Mycroft's own above-average heights.

Of course, it was still entirely possible that Sherlock had just taken in a homeless girl to better integrate her into his "network" or to simply piss off Mycroft. Still, it was the second trait that convinced John that Harriet was a Holmes - that piercing, blade-like shine in her eyes was so similar to that in the Holmes brothers', slicing and dicing through everything around her in a bid to understand it all.

"Do you need help getting things set up for Harriet?" John inquired leadingly. Never mind - the fact that Harriet hadn't run out of here screaming for Child-Protective-Services upon seeing the severed body parts and various other oddities was the biggest indicator that she was a Holmes.

"No, we're good," Harriet piped up without looking up from the bubbling mixture. "I hope that you don't mind that I've taken your old room, Dr. Watson?"

"Not at all. Feel free to decorate it however you want."

"Oh, that's all right. I spend most of time with my experiments in the living room anyway," she replied cheerfully.

"I never understood why you spent so much time tidying up your room, John," Sherlock said dismissively.

"Because I wanted to be able to reach my bed and get back out quickly without having to wade through a trash pile, Sherlock. I mean, I'm not a neat-freak -"

"I never said you were. You are a bit insistent on proper placement and organization though - possibly a relic of your military days?"

John chuckled. Definitely from his stint in Afghanistan, where he and his comrades might have to pack up and move out at a moment's notice. Still, he was never quite as much of a slob as Sherlock though.

"He kind of has a point, Sherlock," Harriet said with a tinge of amusement coloring her voice. "I mean, if you're trying to make it impossible for Mycroft or Mrs. Hudson to search the place for your stash, then you're underestimating their resolve, especially since Mycroft will just get his lackies to do it for him."

Sherlock scowled.

"Oh, grow up," she fired back. "Dr. Watson," she inclined her head at John, "would've done the same. Heavens, he's been at you to quit your smoking and cocaine habits almost since you first met!"

"But I'm so boooored!" Sherlock whined (not that he would ever admit to doing so, even under the pain of death). "We haven't had any cases since those two during your first week here! I need stimulation, Harriet! John, back me up here."

"Sorry, Sherlock, I'm with her on this one."

Sherlock scowled. "She helped Mrs. Hudson confiscate my bullets too! I've had to settle for futile pumping the trigger of this thing-" he raised and shook the gun in his left hand irritably - "as though it were one of those stupid stress balls."

"She offered me freshly baked treacle tart. I couldn't possibly let her largesse go unrewarded," Harriet stated serenely. "Quid quo pro, Sherlock."

Sherlock growled and stomped over to the kitchen table, which was currently playing host to two Erlenmeyer flasks connected by a complex web of tubes; the flask on the left contained solid blue cubes floating in a reddish mixture, and the tubes seemed to be funneling the greenish vapors into the other flask.

John was pretty sure that chemistry was not supposed to work that way, but then again, this was more Sherlock's sort of thing. At least as long as the blue cubes weren't meth - in that event, there would have to be an intervention...

Clearing his throat and shaking himself free from his thoughts, John got straight down to the purpose of his visit, "So, best man?"

Harriet stopped her stirring and looked up at the pair with wide-eyes.

"Best man?" Sherlock queried bemusedly. "That is a toss-up between Billy Kincaid and Joseph Kincade."

"Sorry?"

"You know, Billy Kincaid the Camden Garroter. Made substantial, anonymous donations to charity that remain untraced to this day. Yes, he garroted quite a few people every once in a while, but on the balance, his philanthropy saved far more lives. As for Joseph Kincade, he raised one of my more benighted relatives, who favored womanizing and explosions over proper scientific endeavors. Poor man - having raised several generations of Holmes, I'm not how he put up with that one."

"He's talking about you being the best man for his wedding, Sherlock," Harriet piped up, recovering quickly from her surprise and rolling her eyes. "Congratulations, Dr. Watson," she followed up warmly.

"Thank you," he replied automatically. He continued to look intently though at the consulting detective.

"Sherlock?"

The detective was completely frozen. His blue eyes were far wider than normal and remained fixed on Watson; had he been a lesser man, his mouth would have been hanging wide-open as well.

"Oh dear, I think you've broken him," Harriet smirked. "Could you please wait a moment?"

She scrambled over to the kitchen with a permanent marker in hand, climbed on top of a chair, and began drawing a cartoonish, twirly mustache on Sherlock's clean-shaven face.

"Hmmm, still not out of it yet? Eh, more time for me to practice my artistic skills."

And Harriet went on to add a pointy, triangular beard. Unfortunately, this is when Sherlock recovered from his Blue-Screen-of-Death.

"Best man," he echoed, "for your wedding." Just in time too - Harriet had just finished adding the beard a second ago and was seriously considering including cat whiskers in her collection as well.

"Yes. Sherlock Holmes, I want you as the best man for my wedding."

"What about, what's his name, Geoffrey Lestrade?"

"You mean, Greg," John said wearily. "Sure, we have a cuppa every now and then, but YOU'RE my best friend. Sherlock, I can think of no one better to serve as the best man in my wedding, and Mary agrees whole-heartedly."

"John, I...I would be honored," Sherlock responded immediately.

"Wonderful! Mary and I will drop by a bit frequently in the coming weeks since we could really use your input on the wedding plans."

"Of course, of course," Sherlock waved off customarily, having regained his sangroid and turning his attentions back to his experiment.

"Do you want some tea, by any chance, Dr. Watson?" Harriet inquired politely.

"Oh, yes, totally forgot! Tea, John?" Sherlock said, raising his own cup. While he did not possess even a fraction of Sherlock's deductive skills, John could swear that he had seen an eyeball floating in that cup.

"No, I'm good, thank you."

"If it's the eyeball, don't worry - I was going to make you a fresh cup now anyway, not force you to drink the swill that's been out for hours," Harriet said with amusement.

Sherlock turned to Harriet puzzled. "You make the tea?"

"Well, Mrs. Hudson used to, but she got tired of having to clean up afterwards, especially when you just left it willy-nilly, half-drunk. Said something about how she's your landlady and not your housekeeper? So I make it now."

"Hm," Sherlock said thoughtfully. "And I suppose -"

"Yes, Mrs. Hudson was kind enough to inform me of how Dr. Watson enjoys his tea as well. I'll be right back, Dr. Watson."

With that, Harriet gracefully scurried off.

Sherlock took another sip from his cup and grimaced. "This isn't tea! This is just water with food-coloring!"

Harriet laughed even as her hands flew while preparing the tea. "I wondered when you'd notice. I've been giving you that for the past two days now, and it took Dr. Watson's visit for you to finally _observe_ that."

Dr. John Watson was a good, kind man, but he couldn't help but wish that she had dosed the detective with a hallucinogen - just for old time's sake. See how he liked it when the shoe was on the other foot, so to speak.

"So, are you planning on inviting Harry then?"

"No, God, no."

At that, he saw Harriet's back stiffen and her movements become a bit jerky. "I mean, my sister Harry," the good doctor rushed to clarify. "We're not exactly on the best of terms."

"Oh," Harriet said softly, her body relaxing once again. She subtly looked to Sherlock, but the detective remained as oblivious as ever.

Sighing, John added, "In case I did not make it clear, you are invited as well, Harriet."

"Of course, she is," Sherlock said bemusedly. "She's with me, John. I don't see why you need to repeat yourself - Harriet's not like other dull little children."

"Yes, well, I -" John blinked as a cup of tea appeared in front of the duo at the table. Harriet had quietly taken a seat at the tea and was looking at Sherlock with shining eyes.

He would have continued, but the tea's aroma was too enticing. John took a sip and was astonished to find that it was prepared to his specifications - a bit of cream, no sugar, and just a little warm from a touch of cinnamon. There was also a hint of lemon balm that, surprisingly, blended well with the overall mix.

"This is very good, Harriet, very good. Thank you," he said, sipping thoughtfully.

Harriet blushed and looked off to the side.

Perhaps it was because she was just a child, but Harriet had still not acquired the Holmes brothers' impassivity and supreme contempt for the rest of the world yet. Although it was John's personal opinion that the latter was more a mask and protective shield than anything else.

'I'm...I'm looking at a younger Sherlock here," he marveled. Sherlock may have been his best friend and an incredible detective, but John was not blind to his faults. "Well, I suppose that Mary and I will have to step in, visit every once in a while, and teach her about dealing with norms like myself, if only so that she won't have to put up with half of the shit that Sherlock must have dealt with."

And maybe it was just the quality of the tea or her overall warmth and cheer or her humility - but Harriet was still innocent in a way that the Holmes brothers seemed to have long ago shed off, and John, given his own abysmal childhood, wanted to preserve that to the best of his abilities.

"The lemon balm was a capital idea," he praised Harriet.

"Well, from what I could discern from the ingredients that Mrs. Hudson supplied me with," Harriet admitted with a shy smile and ducked head, "it seemed to mesh well with the overall mix of sweetness and spice - you've really got a balancing theme going on."

"I never understood why you had such rigorous expectations for your tea, John. It's just tea," Sherlock said, rolling his eyes.

"And that's why you got water with food-coloring," Harriet smirked, regaining her earlier jocular attitude.

"Hmph. You do know that this means war?"

"And that's my cue to leave," John said quickly, gathering the tea cup and moving towards the door.

'Mrs. Hudson would understand, right? I'll just return the cup during my next visit,' he thought to himself. 'Well, no matter - I'm NOT giving up this tea.'

* * *

 _Clean, well-moisturized hands; the intense scent of men's deodorant counterbalanced by the floral whiff of aftershave; coiffed hair; well-pressed, freshly-laundered clothes - all indicate a high-degree of self-consciousness and a generally well-to-do professional status. Constant flexing of fingers and rotating of wrists suggest early stages of Carpal Tunnel Syndrome, usually seen in jobs involving heavy typing. Consider tapping foot in conjunction with above, indicative of highly impatient personality - so, programmer and aggressive social climber, looking to make inroads in the financial centres of London._

Sherlock quickly glanced away from the man sitting across from him and down at Harriet's own notes, gathered from the information that she'd pulled from various online sources. Given that it was a specialization that he was lacking in (mostly since he could always badger Mycroft to spare one of his techies whenever there was a pressing need), he had encouraged Harriet to look into Python and the fundamentals of programming. Judging by the succinct yet informative section on this man's tweets, he was pleased to see that her early forays had yielded already yielded such bountiful results.

At that moment, Harriet interjected by passing him a slip of paper. Sherlock furrowed his brows as he considered her observations. _She correctly deduced that he is extremely concerned about his appearance but missed the onset of Carpal Tunnel Syndrome; also managed to surmise that he was well-to-do but got no further. Interesting hypothesis that meticulous appearance is part of active social life - gets part of the way to the "aggressive-social-climber." Hmm, will have to introduce her to some of the tells that various professionals show._

Having collected his thoughts (all within half-a-minute, during which David looked aimlessly around the room - _easily distracted_ ), Sherlock began, "David Weatherby, let us cut to the chase."

"What? Oh, pardon me - I was merely, er, admiring your flat." It was obvious that David had been...discomfited by the half-vivisected carcass on the dining table a room over and the overall disordered nature of the flat. "So, I presume that you wanted to review my role as the usher?"

"No, I want to discuss your relationship with Mary Morstan, whom you dated for a period of six months. Not too long before she met John Watson, in fact. What is the current nature of your relations with her?"

David blinked in surprise and chuckled uncomfortably. He stammered, "Well, that is...we're friends, good friends, that's it."

"Hmph. Pardon me for being a bit skeptical. Regardless of time or location, you respond to her tweets within five minutes on average, so you have her on high text alert. In all of your tagged Facebook photos of happy couple, Mary always takes centre frame while John is partially or entirely excluded. Both your Tweets and Facebook replies have offered her a shoulder to cry on on no less than three occasions."

"Don't forget the Tweet-storm after she announced her nuptials," Harriet interjected with a hint of a smirk. "The ones with links to Picasa photos of various professional parties, where he was all dressed up in a suit and had multiple women hanging off his arms."

"Yes, quite true, Harriet. Do you have anything to say in your defense, sir?"

"What the -?!"

"It seems not," Sherlock overrode David's protests smoothly. "Well, then, going forward, we'll downgrade you to casual acquaintance with no more than three annual planned social encounters, all in John's presence of course." Having finished his spiel, he looked at David faux-solicitously. "I trust that was sufficiently clear."

"Dear God, they were right about you," David muttered wide-eyed. "You are a bloody psychopath."

"Well, that's just rude. I'm pretty sure that LinkedIn recruiter you've been chatting up wouldn't appreciate being called that, given that _s_ _he's_ going to do pretty much the same thing if they decide to hire you - minus Sherlock's awesomeness of course," Harriet retorted irritably. "Ditto for someone in GCHQ." 'Thank Mycroft for laughing out the notion of privacy within a week of my arrival here.'

 _Hmm, it appears that she didn't miss a step with her deductions then, thanks to her research._

"It's quite all right, Harriet," Sherlock waved her off. "As long as David here keeps our conversation in mind - and remembers that I am a _high-functioning sociopath_."

He accentuated the final bit with a maniacal, beaver-like grin. "We have your number, and we will be in touch."

* * *

"Whenever the camera points at you, smile. Besides that, keep track of the rings. That's it," Sherlock summed up.

"No," the curly-haired boy, Archie, responded mulishly.

"Fine. Harriet, do you mind?"

"Not at all, Sherlock."

Having hammered out the details, the three sat back in satisfied silence. Archie was soon struck by a thought, however, "Mum expects me to be the page-boy. She's not going to be happy if she hears that I just gave it up."

"Then, say nothing for now, and pretend to be sick on the day of. I'll step in at that point," Harriet suggested. That's what Dudley would have done at any rate, once he realized that being page boy meant that he had to stick by the adults and couldn't run off with his friends. Then again, ickle-Duddikins would have shamelessly thrown a tantrum at that point, and his parents would have just as shamelessly acquiesced.

"How do I do that?" the ten-year old boy inquired curiously.

Harriet handed him a small, purple-wrapped object in the shape of a lollipop.

Sherlock's eyelid twitched upon seeing the "candy." "Ah, yes, I can attest to its effectiveness. Just be sure to sit next to the bathroom for the half-hour that the symptoms last." He would know, thanks to the prank war that had erupted after John's visit.

Once again, the three relapsed into silence. Within mere moments though, Archie began fidgeting restlessly, and his attention was quickly caught by the cadaver on the dining table.

"Huh. Is that a dead body?"

"Yep."

"And you're cutting it open? What is it that you do?"

"I'm a consulting detective." Here, Sherlock paused. "Do you want to watch me cut up the rest of it?"

In response, Archie scampered over to the table. "Cool, maggots!"

'As long as Archie understands that what happens in 221B stays in 221B,' Harriet thought to herself wryly, 'we should be fine, lest his mother kill us for corrupting his impressionable mind. But honestly, of all the things to focus on during a dissection, he picks the maggots?'

* * *

The black-haired pair stared at their reflections in the mirror.

Sherlock broke the silence. "Unto the breach, Harriet." Somewhat unusually for the detective, the declaration was almost tentative and inquisitive in nature rather than bold and imperative.

"Right behind you, Sherlock."


End file.
